Here are the sizes of drill required to produce the required thread. For each line the first part is the size of screw followed by the threads per inch or in metric the pitch. For example 4 40 is a size 4 screw with 40 threads per inch. While M 2 0.40 is a metric 2mm with a 0.40mm pitch, the distances between one peak to the next. Depending on what kind of material being tapped the size of hole will vary. When taping by hand use 90% to 50% and when using power tools use 80% through 50%. The most common used size drill is 75%. For sheet brass, sheet nickel, babbitt, white metal, hard rubber use 75% to 80%. For mild steel, aluminum, cast iron, and cast brass use 70% to 75%. For bronze, tool steel, drop forging, stainless steel, cast steel, nickel, and copper use 65% to 70%. This table list the actual size of drill wanted there may not be an exact match use the next large drill you can purchase.

 

    Size  diam.   100%   95%   90%   85%   80%   75%   70%   65%   60%   55%   50%

    4  40 .1120  .0795 .0811 .0828 .0844 .0860 .0876 .0893 .0909 .0925 .0941 .0958

    6  32 .1380  .0974 .0994 .1015 .1035 .1055 .1076 .1096 .1116 .1136 .1157 .1177

    8  32 .1640  .1234 .1254 .1275 .1295 .1315 .1336 .1356 .1376 .1396 .1417 .1437

   10  24 .1900  .1359 .1386 .1413 .1440 .1467 .1494 .1521 .1548 .1575 .1602 .1629

   10  32 .1900  .1494 .1514 .1535 .1555 .1575 .1596 .1616 .1636 .1656 .1677 .1697

   12  24 .2160  .1619 .1646 .1673 .1700 .1727 .1754 .1781 .1808 .1835 .1862 .1889

   12  28 .2160  .1696 .1719 .1742 .1766 .1789 .1812 .1835 .1858 .1882 .1905 .1928

 

 1/ 4  20 .2500  .1850 .1883 .1915 .1948 .1980 .2013 .2045 .2078 .2110 .2143 .2175

 1/ 4  28 .2500  .2036 .2059 .2082 .2106 .2129 .2152 .2175 .2198 .2222 .2245 .2268

 5/16  18 .3125  .2403 .2439 .2475 .2512 .2548 .2584 .2620 .2656 .2692 .2728 .2764

 5/16  24 .3125  .2584 .2611 .2638 .2665 .2692 .2719 .2746 .2773 .2800 .2827 .2854

 3/ 8  16 .3750  .2938 .2979 .3019 .3060 .3100 .3141 .3182 .3222 .3263 .3303 .3344

 3/ 8  24 .3750  .3209 .3236 .3263 .3290 .3317 .3344 .3371 .3398 .3425 .3452 .3479

 7/16  14 .4375  .3447 .3494 .3540 .3586 .3633 .3679 .3725 .3772 .3818 .3865 .3911

 7/16  20 .4375  .3725 .3758 .3790 .3823 .3855 .3888 .3920 .3953 .3985 .4018 .4050

 1/ 2  13 .5000  .4001 .4051 .4101 .4151 .4201 .4251 .4301 .4350 .4400 .4450 .4500

 1/ 2  20 .5000  .4350 .4383 .4415 .4448 .4480 .4513 .4545 .4578 .4610 .4643 .4675

 5/ 8  11 .6250  .5069 .5128 .5187 .5246 .5305 .5364 .5423 .5482 .5541 .5600 .5660

 5/ 8  18 .6250  .5528 .5564 .5600 .5637 .5673 .5709 .5745 .5781 .5817 .5853 .5889

 

M  2 0.40 .0787  .0583 .0593 .0603 .0614 .0624 .0634 .0644 .0654 .0665 .0675 .0685

M  2 0.25 .0787  .0660 .0666 .0672 .0679 .0685 .0692 .0698 .0704 .0711 .0717 .0723

M  3 0.50 .1181  .0925 .0938 .0951 .0964 .0977 .0989 .1002 .1015 .1028 .1040 .1053

M  3 0.35 .1181  .1002 .1011 .1020 .1029 .1038 .1047 .1056 .1065 .1074 .1083 .1092

M  4 0.70 .1575  .1217 .1235 .1253 .1271 .1288 .1306 .1324 .1342 .1360 .1378 .1396

M  4 0.50 .1575  .1319 .1332 .1345 .1357 .1370 .1383 .1396 .1409 .1421 .1434 .1447

M  5 0.80 .1969  .1559 .1580 .1600 .1621 .1641 .1662 .1682 .1703 .1723 .1743 .1764

M  5 0.50 .1969  .1713 .1726 .1738 .1751 .1764 .1777 .1790 .1802 .1815 .1828 .1841

M  6 1.00 .2362  .1851 .1876 .1902 .1927 .1953 .1979 .2004 .2030 .2055 .2081 .2106

M  6 0.75 .2362  .1979 .1998 .2017 .2036 .2055 .2075 .2094 .2113 .2132 .2151 .2170

M  7 1.00 .2756  .2244 .2270 .2296 .2321 .2347 .2372 .2398 .2423 .2449 .2475 .2500

M  7 0.75 .2756  .2372 .2392 .2411 .2430 .2449 .2468 .2487 .2507 .2526 .2545 .2564

M  8 1.25 .3150  .2510 .2542 .2574 .2606 .2638 .2670 .2702 .2734 .2766 .2798 .2830

M  8 1.00 .3150  .2638 .2664 .2689 .2715 .2740 .2766 .2792 .2817 .2843 .2868 .2894

M  8 0.75 .3150  .2766 .2785 .2804 .2824 .2843 .2862 .2881 .2900 .2919 .2939 .2958

M 10 1.50 .3937  .3170 .3208 .3247 .3285 .3323 .3362 .3400 .3438 .3477 .3515 .3553

M 10 1.25 .3937  .3298 .3330 .3362 .3394 .3426 .3458 .3490 .3521 .3553 .3585 .3617

M 10 1.00 .3937  .3426 .3451 .3477 .3502 .3528 .3553 .3579 .3605 .3630 .3656 .3681

M 10 0.75 .3937  .3553 .3573 .3592 .3611 .3630 .3649 .3669 .3688 .3707 .3726 .3745

M 12 1.75 .4724  .3829 .3874 .3919 .3964 .4008 .4053 .4098 .4143 .4187 .4232 .4277

M 12 1.50 .4724  .3957 .3996 .4034 .4072 .4111 .4149 .4187 .4226 .4264 .4302 .4341

M 12 1.25 .4724  .4085 .4117 .4149 .4181 .4213 .4245 .4277 .4309 .4341 .4373 .4405

M 12 1.00 .4724  .4213 .4239 .4264 .4290 .4315 .4341 .4366 .4392 .4418 .4443 .4469


Here are the sizes of drill required to produce the required thread. For each line the first part is the size of screw followed by the threads per inch or in metric the pitch. For example 4 40 is a size 4 screw with 40 threads per inch. While M 2 0.40 is a metric 2mm with a 0.40mm pitch, the distances between one peak to the next. Depending on what kind of material being tapped the size of hole will vary. When taping by hand use 90% to 50% and when using power tools use 80% through 50%. The most common used size drill is 75%. For sheet brass, sheet nickel, babbitt, white metal, hard rubber use 75% to 80%. For mild steel, aluminum, cast iron, and cast brass use 70% to 75%. For bronze, tool steel, drop forging, stainless steel, cast steel, nickel, and copper use 65% to 70%. This table lists the next available American drill except for the letter drills use the next larger size.

 

    Size  diam.   100%   95%   90%   85%   80%   75%   70%   65%   60%   55%   50%

    4  40 .1120   #46   #46   #44   #44   #44   #43   #43   #42   #42   3/32  #41

    6  32 .1380   #40   #39   #38   #37   #36   7/64  7/64  #34   #33   #32   #31

    8  32 .1640   1/ 8  1/ 8  #30   #29   #29   #29   #29   #28   #28   #27   #27

   10  24 .1900   #29   #28   #28   #27   #26   #25   #24   #23   #22   #20   #19

   10  32 .1900   #25   #24   #23   5/32  #22   #21   #20   #19   #19   #18   #18

   12  24 .2160   #20   #19   #18   #18   11/64 #16   #15   #15   #13   3/16  #12

   12  28 .2160   #18   11/64 #16   #16   #15   #14   #13   #13   3/16  #11   #10

 

 1/ 4  20 .2500   #13   3/16  #11   # 9   # 8   # 7   # 6   # 4   # 3   7/32  7/32

 1/ 4  28 .2500   13/64 # 5   # 4   # 3   # 3   7/32  7/32  7/32  # 2   # 1   # 1

 5/16  18 .3125   C     D     D     1/ 4  F     F     G     17/64 I     I     J

 5/16  24 .3125   F     G     17/64 17/64 I     I     J     J     K     9/32  L

 3/ 8  16 .3750   M     19/64 N     5/16  5/16  5/16  P     P     21/64 Q     R

 3/ 8  24 .3750   P     P     21/64 21/64 Q     R     R     R     11/32 11/32 S

 7/16  14 .4375   11/32 S     T     T     U     U     3/ 8  V     W     W     25/64

 7/16  20 .4375   3/ 8  3/ 8  V     W     W     25/64 25/64 X     X     Y     Y

 1/ 2  13 .5000   Y     Y     Z     Z     27/64 7/16  7/16  7/16  29/64 29/64 29/64

 1/ 2  20 .5000   7/16  7/16  29/64 29/64 29/64 29/64 29/64 15/32 15/32 15/32 15/32

 5/ 8  11 .6250   33/64 33/64 33/64 17/32 17/32 35/64 35/64 35/64 18/32 18/32 37/64

 5/ 8  18 .6250   18/32 18/32 18/32 18/32 37/64 37/64 37/64 37/64 19/32 19/32 19/32

 

M  2 0.40 .0787   #53   #53   1/16  1/16  1/16  #52   #51   #51   #51   #50   #50

M  2 0.25 .0787   #51   #51   #51   #50   #50   #50   #50   #49   #49   #49   #49

M  3 0.50 .1181   #42   #42   #41   #41   #40   #39   #38   #38   #37   #37   #36

M  3 0.35 .1181   #38   #38   #38   #37   #37   #36   #36   #36   7/64  7/64  7/64

M  4 0.70 .1575   1/ 8  1/ 8  1/ 8  #30   #30   #29   #29   #29   #29   #28   #28

M  4 0.50 .1575   #29   #29   #29   #29   #28   #28   #28   #28   #27   #27   #27

M  5 0.80 .1969   5/32  #22   #20   #19   #19   #19   #18   #18   11/64 #16   #16

M  5 0.50 .1969   11/64 11/64 #17   #16   #16   #16   #15   #15   #14   #14   #13

M  6 1.00 .2362   #13   3/16  #11   #10   # 9   # 8   # 7   13/64 # 5   # 4   # 3

M  6 0.75 .2362   # 8   # 8   # 7   13/64 # 5   # 4   # 4   # 3   # 3   7/32  7/32

M  7 1.00 .2756   # 1   # 1   A     A     A     B     C     C     D     1/ 4  1/ 4

M  7 0.75 .2756   B     B     C     C     D     D     1/ 4  1/ 4  F     F     F

M  8 1.25 .3150   1/ 4  F     F     G     17/64 17/64 I     I     J     K     L

M  8 1.00 .3150   17/64 17/64 I     I     J     J     K     K     L     L     L

M  8 0.75 .3150   J     J     K     K     L     L     L     L     M     M     M

M 10 1.50 .3937   O     P     P     21/64 Q     R     R     11/32 S     T     T

M 10 1.25 .3937   21/64 Q     R     R     11/32 11/32 S     T     T     T     U

M 10 1.00 .3937   11/32 11/32 S     T     T     T     T     23/64 U     U     U

M 10 0.75 .3937   T     T     T     23/64 U     U     U     U     3/ 8  3/ 8  3/ 8

M 12 1.75 .4724   W     W     25/64 X     Y     Y     Z     Z     27/64 27/64 7/16

M 12 1.50 .4724   X     Y     Y     13/32 Z     Z     27/64 27/64 7/16  7/16  7/16

M 12 1.25 .4724   13/32 Z     Z     27/64 27/64 7/16  7/16  7/16  7/16  7/16  29/64

M 12 1.00 .4724   27/64 27/64 7/16  7/16  7/16  7/16  7/16  7/16  29/64 29/64 29/64


Here are the sizes of drill required to produce the required thread. For each line the first part is the size of screw followed by the threads per inch or in metric the pitch. For example 4 40 is a size 4 screw with 40 threads per inch. While M 2 0.40 is a metric 2mm with a 0.40mm pitch, the distances between one peak to the next. Depending on what kind of material being tapped the size of hole will vary. When taping by hand use 90% to 50% and when using power tools use 80% through 50%. The most common used size drill is 75%. For sheet brass, sheet nickel, babbitt, white metal, hard rubber use 75% to 80%. For mild steel, aluminum, cast iron, and cast brass use 70% to 75%. For bronze, tool steel, drop forging, stainless steel, cast steel, nickel, and copper use 65% to 70%. This table lists the next available American drill except for the letter drills use the next larger size. The percent values after the drill size are the correct values for that drill.

 

    Size  diam.      100%         95%         90%         85%         80%         75%

    4  40 .1120   #46     95% #46     95% #44     80% #44     80% #44     80% #43     71%

    6  32 .1380   #40     99% #39     95% #38     90% #37     84% #36     78% 7/64    70%

    8  32 .1640   1/ 8    96% 1/ 8    96% #30     87% #29     69% #29     69% #29     69%

   10  24 .1900   #29    100% #28     91% #28     91% #27     85% #26     79% #25     75%

   10  32 .1900   #25    100% #24     94% #23     89% 5/32    83% #22     81% #21     76%

   12  24 .2160   #20    102% #19     92% #18     86% #18     86% 11/64   81% #16     72%

   12  28 .2160   #18    100% 11/64   95% #16     84% #16     84% #15     78% #14     73%

 

 1/ 4  20 .2500   #13    100% 3/16    96% #11     91% # 9     83% # 8     79% # 7     75%

 1/ 4  28 .2500   13/64  101% # 5     96% # 4     88% # 3     80% # 3     80% 7/32    67%

 5/16  18 .3125   C       98% D       92% D       92% 1/ 4    87% F       77% F       77%

 5/16  24 .3125   F      103% G       95% 17/64   87% 17/64   87% I       75% I       75%

 3/ 8  16 .3750   M       99% 19/64   96% N       90% 5/16    77% 5/16    77% 5/16    77%

 3/ 8  24 .3750   P       96% P       96% 21/64   87% 21/64   87% Q       79% R       67%

 7/16  14 .4375   11/32  101% S       96% T       86% T       86% U       75% U       75%

 7/16  20 .4375   3/ 8    96% 3/ 8    96% V       93% W       79% W       79% 25/64   72%

 1/ 2  13 .5000   Y       96% Y       96% Z       87% Z       87% 27/64   78% 7/16    63%

 1/ 2  20 .5000   7/16    96% 7/16    96% 29/64   72% 29/64   72% 29/64   72% 29/64   72%

 5/ 8  11 .6250   33/64   93% 33/64   93% 33/64   93% 17/32   79% 17/32   79% 35/64   66%

 5/ 8  18 .6250   18/32   87% 18/32   87% 18/32   87% 18/32   87% 37/64   65% 37/64   65%

 

M  2 0.40 .0787   #53     94% #53     94% 1/16    79% 1/16    79% 1/16    79% #52     74%

M  2 0.25 .0787   #51     92% #51     92% #51     92% #50     68% #50     68% #50     68%

M  3 0.50 .1181   #42     96% #42     96% #41     86% #41     86% #40     79% #39     73%

M  3 0.35 .1181   #38     93% #38     93% #38     93% #37     79% #37     79% #36     65%

M  4 0.70 .1575   1/ 8    91% 1/ 8    91% 1/ 8    91% #30     81% #30     81% #29     60%

M  4 0.50 .1575   #29     84% #29     84% #29     84% #29     84% #28     66% #28     66%

M  5 0.80 .1969   5/32    99% #22     97% #20     88% #19     75% #19     75% #19     75%

M  5 0.50 .1969   11/64   98% 11/64   98% #17     93% #16     78% #16     78% #16     78%

M  6 1.00 .2362   #13    100% 3/16    95% #11     88% #10     84% # 9     79% # 8     73%

M  6 0.75 .2362   # 8     97% # 8     97% # 7     92% 13/64   86% # 5     80% # 4     71%

M  7 1.00 .2756   # 1     93% # 1     93% A       81% A       81% A       81% B       74%

M  7 0.75 .2756   B       98% B       98% C       88% C       88% D       77% D       77%

M  8 1.25 .3150   1/ 4   102% F       91% F       91% G       84% 17/64   77% 17/64   77%

M  8 1.00 .3150   17/64   97% 17/64   97% I       84% I       84% J       74% J       74%

M  8 0.75 .3150   J       99% J       99% K       89% K       89% L       65% L       65%

M 10 1.50 .3937   O      101% P       92% P       92% 21/64   86% Q       80% R       71%

M 10 1.25 .3937   21/64  103% Q       97% R       86% R       86% 11/32   78% 11/32   78%

M 10 1.00 .3937   11/32   98% 11/32   98% S       89% T       70% T       70% T       70%

M 10 0.75 .3937   T       93% T       93% T       93% 23/64   89% U       67% U       67%

M 12 1.75 .4724   W       97% W       97% 25/64   91% X       84% Y       76% Y       76%

M 12 1.50 .4724   X       98% Y       89% Y       89% 13/32   86% Z       77% Z       77%

M 12 1.25 .4724   13/32  103% Z       93% Z       93% 27/64   79% 27/64   79% 7/16    55%

M 12 1.00 .4724   27/64   99% 27/64   99% 7/16    68% 7/16    68% 7/16    68% 7/16    68%


Here are the sizes of drill required to produce the required thread. For each line the first part is the size of screw followed by the threads per inch or in metric the pitch. For example 4 40 is a size 4 screw with 40 threads per inch. While M 2 0.40 is a metric 2mm with a 0.40mm pitch, the distances between one peak to the next. Depending on what kind of material being tapped the size of hole will vary. When taping by hand use 90% to 50% and when using power tools use 80% through 50%. The most common used size drill is 75%. For sheet brass, sheet nickel, babbitt, white metal, hard rubber use 75% to 80%. For mild steel, aluminum, cast iron, and cast brass use 70% to 75%. For bronze, tool steel, drop forging, stainless steel, cast steel, nickel, and copper use 65% to 70%. This table lists the next available American drill except for the letter drills use the next larger size. The percent values after the drill size are the correct values for that drill.

 

    Size  diam.       75%         70%         65%         60%         55%         50%

    4  40 .1120   #43     71% #43     71% #42     57% #42     57% 3/32    56% #41     49%

    6  32 .1380   7/64    70% 7/64    70% #34     67% #33     62% #32     54% #31     44%

    8  32 .1640   #29     69% #29     69% #28     58% #28     58% #27     49% #27     49%

   10  24 .1900   #25     75% #24     70% #23     67% #22     61% #20     54% #19     44%

   10  32 .1900   #21     76% #20     71% #19     59% #19     59% #18     50% #18     50%

   12  24 .2160   #16     72% #15     67% #15     67% #13     57% 3/16    53% #12     50%

   12  28 .2160   #14     73% #13     67% #13     67% 3/16    61% #11     54% #10     48%

 

 1/ 4  20 .2500   # 7     75% # 6     71% # 4     63% # 3     57% 7/32    48% 7/32    48%

 1/ 4  28 .2500   7/32    67% 7/32    67% 7/32    67% # 2     63% # 1     47% # 1     47%

 5/16  18 .3125   F       77% G       71% 17/64   65% I       56% I       56% J       49%

 5/16  24 .3125   I       75% J       66% J       66% K       58% 9/32    58% L       42%

 3/ 8  16 .3750   5/16    77% P       64% P       64% 21/64   58% Q       53% R       44%

 3/ 8  24 .3750   R       67% R       67% R       67% 11/32   58% 11/32   58% S       50%

 7/16  14 .4375   U       75% 3/ 8    67% V       65% W       56% W       56% 25/64   51%

 7/16  20 .4375   25/64   72% 25/64   72% X       62% X       62% Y       52% Y       52%

 1/ 2  13 .5000   7/16    63% 7/16    63% 7/16    63% 29/64   47% 29/64   47% 29/64   47%

 1/ 2  20 .5000   29/64   72% 29/64   72% 15/32   48% 15/32   48% 15/32   48% 15/32   48%

 5/ 8  11 .6250   35/64   66% 35/64   66% 35/64   66% 18/32   53% 18/32   53% 37/64   40%

 5/ 8  18 .6250   37/64   65% 37/64   65% 37/64   65% 19/32   43% 19/32   43% 19/32   43%

 

M  2 0.40 .0787   #52     74% #51     57% #51     57% #51     57% #50     43% #50     43%

M  2 0.25 .0787   #50     68% #50     68% #49     45% #49     45% #49     45% #49     45%

M  3 0.50 .1181   #39     73% #38     65% #38     65% #37     55% #37     55% #36     45%

M  3 0.35 .1181   #36     65% #36     65% #36     65% 7/64    49% 7/64    49% 7/64    49%

M  4 0.70 .1575   #29     60% #29     60% #29     60% #29     60% #28     47% #28     47%

M  4 0.50 .1575   #28     66% #28     66% #28     66% #27     53% #27     53% #27     53%

M  5 0.80 .1969   #19     75% #18     67% #18     67% 11/64   61% #16     49% #16     49%

M  5 0.50 .1969   #16     78% #15     66% #15     66% #14     58% #14     58% #13     46%

M  6 1.00 .2362   # 8     73% # 7     69% 13/64   65% # 5     60% # 4     53% # 3     45%

M  6 0.75 .2362   # 4     71% # 4     71% # 3     61% # 3     61% 7/32    45% 7/32    45%

M  7 1.00 .2756   B       74% C       66% C       66% D       58% 1/ 4    50% 1/ 4    50%

M  7 0.75 .2756   D       77% 1/ 4    67% 1/ 4    67% F       48% F       48% F       48%

M  8 1.25 .3150   17/64   77% I       67% I       67% J       59% K       53% L       39%

M  8 1.00 .3150   J       74% K       66% K       66% L       49% L       49% L       49%

M  8 0.75 .3150   L       65% L       65% L       65% M       52% M       52% M       52%

M 10 1.50 .3937   R       71% R       71% 11/32   65% S       60% T       47% T       47%

M 10 1.25 .3937   11/32   78% S       71% T       56% T       56% T       56% U       40%

M 10 1.00 .3937   T       70% T       70% 23/64   67% U       50% U       50% U       50%

M 10 0.75 .3937   U       67% U       67% U       67% 3/ 8    49% 3/ 8    49% 3/ 8    49%

M 12 1.75 .4724   Y       76% Z       66% Z       66% 27/64   56% 27/64   56% 7/16    39%

M 12 1.50 .4724   Z       77% 27/64   66% 27/64   66% 7/16    46% 7/16    46% 7/16    46%

M 12 1.25 .4724   7/16    55% 7/16    55% 7/16    55% 7/16    55% 7/16    55% 29/64   30%

M 12 1.00 .4724   7/16    68% 7/16    68% 7/16    68% 29/64   38% 29/64   38% 29/64   38%


Here are the sizes of drill required to produce the required thread. For each line the first part is the size of screw followed by the threads per inch or in metric the pitch. For example 4 40 is a size 4 screw with 40 threads per inch. While M 2 0.40 is a metric 2mm with a 0.40mm pitch, the distances between one peak to the next. Depending on what kind of material being tapped the size of hole will vary. When taping by hand use 90% to 50% and when using power tools use 80% through 50%. The most common used size drill is group 2. For sheet brass, sheet nickel, babbitt, white metal, hard rubber use group 1. For mild steel, aluminum, cast iron, and cast brass use group 2. For bronze, tool steel, drop forging, stainless steel, cast steel, nickel, and copper use group 3. This table lists the next available American drill except for the letter drills use the next larger size. Pick the group best suited for you work pick either drill listed. Metric drills have been add as they will become more available.

 

    Size   diam.              group 1           group 2           group 3

                                    /----------------------------\

                  /----------------------------\      /----------------------------\

    4  40 .1120   #44    2.2mm      #43    2.2mm      #43    2.3mm      #42    2.3mm

    6  32 .1380   #36    2.7mm      7/64   2.7mm      7/64   2.8mm      #34    2.8mm

    8  32 .1640   #29    3.3mm      #29    3.4mm      #29    3.4mm      #28    3.5mm

   10  24 .1900   #26    3.7mm      #25    3.8mm      #24    3.9mm      #23    3.9mm

   10  32 .1900   #22    4.0mm      #21    4.1mm      #20    4.1mm      #19    4.2mm

   12  24 .2160   11/64  4.4mm      #16    4.5mm      #15    4.5mm      #15    4.6mm

   12  28 .2160   #15    4.5mm      #14    4.6mm      #13    4.7mm      #13    4.7mm

 

 1/ 4  20 .2500   # 8    5.0mm      # 7    5.1mm      # 6    5.2mm      # 4    5.3mm

 1/ 4  28 .2500   # 3    5.4mm      7/32   5.5mm      7/32   5.5mm      7/32   5.6mm

 5/16  18 .3125   F      6.5mm      F      6.6mm      G      6.7mm      17/64  6.7mm

 5/16  24 .3125   I      6.8mm      I      6.9mm      J      7.0mm      J      7.0mm

 3/ 8  16 .3750   5/16   7.9mm      5/16   8.0mm      P      8.1mm      P      8.2mm

 3/ 8  24 .3750   Q      8.4mm      R      8.5mm      R      8.6mm      R      8.6mm

 7/16  14 .4375   U      9.2mm      U      9.3mm      3/ 8   9.5mm      V      9.6mm

 7/16  20 .4375   W      9.8mm      25/64  9.9mm      25/64 10.0mm      X     10.0mm

 1/ 2  13 .5000   27/64 10.7mm      7/16  10.8mm      7/16  10.9mm      7/16  11.1mm

 1/ 2  20 .5000   29/64 11.4mm      29/64 11.5mm      29/64 11.5mm      15/32 11.6mm

 5/ 8  11 .6250   17/32 13.5mm      35/64 13.6mm      35/64 13.8mm      35/64 13.9mm

 5/ 8  18 .6250   37/64 14.4mm      37/64 14.5mm      37/64 14.6mm      37/64 14.7mm

 

M  2 0.40 .0787   1/16   1.6mm      #52    1.6mm      #51    1.6mm      #51    1.7mm

M  2 0.25 .0787   #50    1.7mm      #50    1.8mm      #50    1.8mm      #49    1.8mm

M  3 0.50 .1181   #40    2.5mm      #39    2.5mm      #38    2.5mm      #38    2.6mm

M  3 0.35 .1181   #37    2.6mm      #36    2.7mm      #36    2.7mm      #36    2.7mm

M  4 0.70 .1575   #30    3.3mm      #29    3.3mm      #29    3.4mm      #29    3.4mm

M  4 0.50 .1575   #28    3.5mm      #28    3.5mm      #28    3.5mm      #28    3.6mm

M  5 0.80 .1969   #19    4.2mm      #19    4.2mm      #18    4.3mm      #18    4.3mm

M  5 0.50 .1969   #16    4.5mm      #16    4.5mm      #15    4.5mm      #15    4.6mm

M  6 1.00 .2362   # 9    5.0mm      # 8    5.0mm      # 7    5.1mm      13/64  5.2mm

M  6 0.75 .2362   # 5    5.2mm      # 4    5.3mm      # 4    5.3mm      # 3    5.4mm

M  7 1.00 .2756   A      6.0mm      B      6.0mm      C      6.1mm      C      6.2mm

M  7 0.75 .2756   D      6.2mm      D      6.3mm      1/ 4   6.3mm      1/ 4   6.4mm

M  8 1.25 .3150   17/64  6.7mm      17/64  6.8mm      I      6.9mm      I      6.9mm

M  8 1.00 .3150   J      7.0mm      J      7.0mm      K      7.1mm      K      7.2mm

M  8 0.75 .3150   L      7.2mm      L      7.3mm      L      7.3mm      L      7.4mm

M 10 1.50 .3937   Q      8.4mm      R      8.5mm      R      8.6mm      11/32  8.7mm

M 10 1.25 .3937   11/32  8.7mm      11/32  8.8mm      S      8.9mm      T      8.9mm

M 10 1.00 .3937   T      9.0mm      T      9.0mm      T      9.1mm      23/64  9.2mm

M 10 0.75 .3937   U      9.2mm      U      9.3mm      U      9.3mm      U      9.4mm

M 12 1.75 .4724   Y     10.2mm      Y     10.3mm      Z     10.4mm      Z     10.5mm

M 12 1.50 .4724   Z     10.4mm      Z     10.5mm      27/64 10.6mm      27/64 10.7mm

M 12 1.25 .4724   27/64 10.7mm      7/16  10.8mm      7/16  10.9mm      7/16  10.9mm

M 12 1.00 .4724   7/16  11.0mm      7/16  11.0mm      7/16  11.1mm      7/16  11.2mm


Here are the sizes of drill required to produce the required thread. For each line the first part is the size of screw followed by the threads per inch or in metric the pitch. For example 4 40 is a size 4 screw with 40 threads per inch. While M 2 0.40 is a metric 2mm with a 0.40mm pitch, the distances between one peak to the next. Depending on what kind of material being tapped the size of hole will vary. When taping by hand use 90% to 50% and when using power tools use 80% through 50%. The most common used size drill is group 2. For sheet brass, sheet nickel, babbitt, white metal, hard rubber use group 1. For mild steel, aluminum, cast iron, and cast brass use group 2. For bronze, tool steel, drop forging, stainless steel, cast steel, nickel, and copper use group 3. This table lists the next available American drill except for the letter drills use the next larger size. Pick the group best suited for you work pick either drill listed. Metric drills have been add as they will become more available. The percent values after the drill size are the correct values for that drill.

 

    Size   diam.              group 1           group 2           group 3

                                   /----------------------------------\

                  /--------------------------------\   /--------------------------------\

Size  diam.             80%               75%               70%               65%

    4  40 .1120   #44   -.0000  80% #43   0.0014  71% #43   -.0003  71% #42   0.0026  57%

    6  32 .1380   #36   0.0010  78% 7/64  0.0018  70% 7/64  -.0002  70% #34   -.0006  67%

    8  32 .1640   #29   0.0045  69% #29   0.0024  69% #29   0.0004  69% #28   0.0029  58%

   10  24 .1900   #26   0.0003  79% #25   0.0001  75% #24   -.0001  70% #23   -.0008  67%

   10  32 .1900   #22   -.0005  81% #21   -.0006  76% #20   -.0006  71% #19   0.0024  59%

   12  24 .2160   11/64 -.0008  81% #16   0.0016  72% #15   0.0019  67% #15   -.0008  67%

   12  28 .2160   #15   0.0011  78% #14   0.0008  73% #13   0.0015  67% #13   -.0008  67%

 

 1/ 4  20 .2500   # 8   0.0010  79% # 7   -.0003  75% # 6   -.0005  71% # 4   0.0012  63%

 1/ 4  28 .2500   # 3   0.0001  80% 7/32  0.0036  67% 7/32  0.0013  67% 7/32  -.0010  67%

 5/16  18 .3125   F     0.0022  77% F     -.0014  77% G     -.0010  71% 17/64 0.0000  65%

 5/16  24 .3125   I     0.0028  75% I     0.0001  75% J     0.0024  66% J     -.0003  66%

 3/ 8  16 .3750   5/16  0.0025  77% 5/16  -.0016  77% P     0.0048  64% P     0.0008  64%

 3/ 8  24 .3750   Q     0.0003  79% R     0.0046  67% R     0.0019  67% R     -.0008  67%

 7/16  14 .4375   U     0.0047  75% U     0.0001  75% 3/ 8  0.0025  67% V     -.0002  65%

 7/16  20 .4375   W     0.0005  79% 25/64 0.0018  72% 25/64 -.0014  72% X     0.0017  62%

 1/ 2  13 .5000   27/64 0.0018  78% 7/16  0.0124  63% 7/16  0.0074  63% 7/16  0.0025  63%

 1/ 2  20 .5000   29/64 0.0051  72% 29/64 0.0018  72% 29/64 -.0014  72% 15/32 0.0110  48%

 5/ 8  11 .6250   17/32 0.0008  79% 35/64 0.0105  66% 35/64 0.0046  66% 35/64 -.0013  66%

 5/ 8  18 .6250   37/64 0.0108  65% 37/64 0.0072  65% 37/64 0.0036  65% 37/64 0.0000  65%

 

M  2 0.40 .0787   1/16  0.0001  79% #52   0.0001  74% #51   0.0026  57% #51   0.0016  57%

M  2 0.25 .0787   #50   0.0015  68% #50   0.0008  68% #50   0.0002  68% #49   0.0026  45%

M  3 0.50 .1181   #40   0.0003  79% #39   0.0006  73% #38   0.0013  65% #38   0.0000  65%

M  3 0.35 .1181   #37   0.0002  79% #36   0.0018  65% #36   0.0009  65% #36   0.0000  65%

M  4 0.70 .1575   #30   -.0003  81% #29   0.0054  60% #29   0.0036  60% #29   0.0018  60%

M  4 0.50 .1575   #28   0.0035  66% #28   0.0022  66% #28   0.0009  66% #28   -.0004  66%

M  5 0.80 .1969   #19   0.0019  75% #19   -.0002  75% #18   0.0013  67% #18   -.0008  67%

M  5 0.50 .1969   #16   0.0006  78% #16   -.0007  78% #15   0.0010  66% #15   -.0002  66%

M  6 1.00 .2362   # 9   0.0007  79% # 8   0.0011  73% # 7   0.0006  69% 13/64 0.0001  65%

M  6 0.75 .2362   # 5   -.0000  80% # 4   0.0015  71% # 4   -.0004  71% # 3   0.0017  61%

M  7 1.00 .2756   A     -.0007  81% B     0.0008  74% C     0.0022  66% C     -.0003  66%

M  7 0.75 .2756   D     0.0011  77% D     -.0008  77% 1/ 4  0.0013  67% 1/ 4  -.0007  67%

M  8 1.25 .3150   17/64 0.0018  77% 17/64 -.0014  77% I     0.0018  67% I     -.0014  67%

M  8 1.00 .3150   J     0.0030  74% J     0.0004  74% K     0.0018  66% K     -.0007  66%

M  8 0.75 .3150   L     0.0057  65% L     0.0038  65% L     0.0019  65% L     -.0000  65%

M 10 1.50 .3937   Q     -.0003  80% R     0.0028  71% R     -.0010  71% 11/32 -.0000  65%

M 10 1.25 .3937   11/32 0.0012  78% 11/32 -.0020  78% S     -.0010  71% T     0.0059  56%

M 10 1.00 .3937   T     0.0052  70% T     0.0027  70% T     0.0001  70% 23/64 -.0011  67%

M 10 0.75 .3937   U     0.0050  67% U     0.0031  67% U     0.0011  67% U     -.0008  67%

M 12 1.75 .4724   Y     0.0032  76% Y     -.0013  76% Z     0.0032  66% Z     -.0013  66%

M 12 1.50 .4724   Z     0.0019  77% Z     -.0019  77% 27/64 0.0032  66% 27/64 -.0007  66%

M 12 1.25 .4724   27/64 0.0006  79% 7/16  0.0130  55% 7/16  0.0098  55% 7/16  0.0066  55%

M 12 1.00 .4724   7/16  0.0060  68% 7/16  0.0034  68% 7/16  0.0009  68% 7/16  -.0017  68%


Here are the sizes of drill required to produce the required thread. For each line the first part is the size of screw followed by the threads per inch or in metric the pitch. For example 4 40 is a size 4 screw with 40 threads per inch. While M 2 0.40 is a metric 2mm with a 0.40mm pitch, the distances between one peak to the next. Depending on what kind of material being tapped the size of hole will vary. When taping by hand use 90% to 50% and when using power tools use 80% through 50%. The most common used size drill is group 2. For sheet brass, sheet nickel, babbitt, white metal, hard rubber use group 1. For mild steel, aluminum, cast iron, and cast brass use group 2. For bronze, tool steel, drop forging, stainless steel, cast steel, nickel, and copper use group 3. This table lists the next available American drill except for the letter drills use the next larger size. Pick the group best suited for you work pick either drill listed. Metric drills have been add as they will become more available. Note letter drills have been substituted for the next larger fractional drill.

 

    Size   diam.              group 1           group 2           group 3

                                    /----------------------------\

                  /----------------------------\      /----------------------------\

    4  40 .1120   #44    2.2mm      #43    2.2mm      #43    2.3mm      #42    2.3mm

    6  32 .1380   #36    2.7mm      7/64   2.7mm      7/64   2.8mm      #34    2.8mm

    8  32 .1640   #29    3.3mm      #29    3.4mm      #29    3.4mm      #28    3.5mm

   10  24 .1900   #26    3.7mm      #25    3.8mm      #24    3.9mm      #23    3.9mm

   10  32 .1900   #22    4.0mm      #21    4.1mm      #20    4.1mm      #19    4.2mm

   12  24 .2160   11/64  4.4mm      #16    4.5mm      #15    4.5mm      #15    4.6mm

   12  28 .2160   #15    4.5mm      #14    4.6mm      #13    4.7mm      #13    4.7mm

 

 1/ 4  20 .2500   # 8    5.0mm      # 7    5.1mm      # 6    5.2mm      # 4    5.3mm

 1/ 4  28 .2500   # 3    5.4mm      7/32   5.5mm      7/32   5.5mm      7/32   5.6mm

 5/16  18 .3125   17/64  6.5mm      17/64  6.6mm      17/64  6.7mm      17/64  6.7mm

 5/16  24 .3125   9/32   6.8mm      9/32   6.9mm      9/32   7.0mm      9/32   7.0mm

 3/ 8  16 .3750   5/16   7.9mm      5/16   8.0mm      21/64  8.1mm      21/64  8.2mm

 3/ 8  24 .3750   11/32  8.4mm      11/32  8.5mm      11/32  8.6mm      11/32  8.6mm

 7/16  14 .4375   3/ 8   9.2mm      3/ 8   9.3mm      3/ 8   9.5mm      25/64  9.6mm

 7/16  20 .4375   25/64  9.8mm      25/64  9.9mm      25/64 10.0mm      13/32 10.0mm

 1/ 2  13 .5000   27/64 10.7mm      7/16  10.8mm      7/16  10.9mm      7/16  11.1mm

 1/ 2  20 .5000   29/64 11.4mm      29/64 11.5mm      29/64 11.5mm      15/32 11.6mm

 5/ 8  11 .6250   17/32 13.5mm      35/64 13.6mm      35/64 13.8mm      35/64 13.9mm

 5/ 8  18 .6250   37/64 14.4mm      37/64 14.5mm      37/64 14.6mm      37/64 14.7mm

 

M  2 0.40 .0787   1/16   1.6mm      #52    1.6mm      #51    1.6mm      #51    1.7mm

M  2 0.25 .0787   #50    1.7mm      #50    1.8mm      #50    1.8mm      #49    1.8mm

M  3 0.50 .1181   #40    2.5mm      #39    2.5mm      #38    2.5mm      #38    2.6mm

M  3 0.35 .1181   #37    2.6mm      #36    2.7mm      #36    2.7mm      #36    2.7mm

M  4 0.70 .1575   #30    3.3mm      #29    3.3mm      #29    3.4mm      #29    3.4mm

M  4 0.50 .1575   #28    3.5mm      #28    3.5mm      #28    3.5mm      #28    3.6mm

M  5 0.80 .1969   #19    4.2mm      #19    4.2mm      #18    4.3mm      #18    4.3mm

M  5 0.50 .1969   #16    4.5mm      #16    4.5mm      #15    4.5mm      #15    4.6mm

M  6 1.00 .2362   # 9    5.0mm      # 8    5.0mm      # 7    5.1mm      13/64  5.2mm

M  6 0.75 .2362   # 5    5.2mm      # 4    5.3mm      # 4    5.3mm      # 3    5.4mm

M  7 1.00 .2756   15/64  6.0mm      1/ 4   6.0mm      1/ 4   6.1mm      1/ 4   6.2mm

M  7 0.75 .2756   1/ 4   6.2mm      1/ 4   6.3mm      1/ 4   6.3mm      1/ 4   6.4mm

M  8 1.25 .3150   17/64  6.7mm      17/64  6.8mm      9/32   6.9mm      9/32   6.9mm

M  8 1.00 .3150   9/32   7.0mm      9/32   7.0mm      9/32   7.1mm      9/32   7.2mm

M  8 0.75 .3150   19/64  7.2mm      19/64  7.3mm      19/64  7.3mm      19/64  7.4mm

M 10 1.50 .3937   11/32  8.4mm      11/32  8.5mm      11/32  8.6mm      11/32  8.7mm

M 10 1.25 .3937   11/32  8.7mm      11/32  8.8mm      23/64  8.9mm      23/64  8.9mm

M 10 1.00 .3937   23/64  9.0mm      23/64  9.0mm      23/64  9.1mm      23/64  9.2mm

M 10 0.75 .3937   3/ 8   9.2mm      3/ 8   9.3mm      3/ 8   9.3mm      3/ 8   9.4mm

M 12 1.75 .4724   13/32 10.2mm      13/32 10.3mm      27/64 10.4mm      27/64 10.5mm

M 12 1.50 .4724   27/64 10.4mm      27/64 10.5mm      27/64 10.6mm      27/64 10.7mm

M 12 1.25 .4724   27/64 10.7mm      7/16  10.8mm      7/16  10.9mm      7/16  10.9mm

M 12 1.00 .4724   7/16  11.0mm      7/16  11.0mm      7/16  11.1mm      7/16  11.2mm


Here are the sizes of drill required to produce the required thread. For each line the first part is the size of screw followed by the threads per inch or in metric the pitch. For example 4 40 is a size 4 screw with 40 threads per inch. While M 2 0.40 is a metric 2mm with a 0.40mm pitch, the distances between one peak to the next. Depending on what kind of material being tapped the size of hole will vary. When taping by hand use 90% to 50% and when using power tools use 80% through 50%. The most common used size drill is group 2. For sheet brass, sheet nickel, babbitt, white metal, hard rubber use group 1. For mild steel, aluminum, cast iron, and cast brass use group 2. For bronze, tool steel, drop forging, stainless steel, cast steel, nickel, and copper use group 3. This table lists the next available American drill except for the letter drills use the next larger size. Pick the group best suited for you work pick either drill listed. Metric drills have been add as they will become more available. Note letter drills have been substituted for the next larger fractional drill.The percent values after the drill size are the correct values for that drill.

 

    Size   diam.              group 1           group 2           group 3

                                   /----------------------------------\

                  /--------------------------------\   /--------------------------------\

Size  diam.             80%               75%               70%               65%

    4  40 .1120   #44   -.0000  80% #43   0.0014  71% #43   -.0003  71% #42   0.0026  57%

    6  32 .1380   #36   0.0010  78% 7/64  0.0018  70% 7/64  -.0002  70% #34   -.0006  67%

    8  32 .1640   #29   0.0045  69% #29   0.0024  69% #29   0.0004  69% #28   0.0029  58%

   10  24 .1900   #26   0.0003  79% #25   0.0001  75% #24   -.0001  70% #23   -.0008  67%

   10  32 .1900   #22   -.0005  81% #21   -.0006  76% #20   -.0006  71% #19   0.0024  59%

   12  24 .2160   11/64 -.0008  81% #16   0.0016  72% #15   0.0019  67% #15   -.0008  67%

   12  28 .2160   #15   0.0011  78% #14   0.0008  73% #13   0.0015  67% #13   -.0008  67%

 

 1/ 4  20 .2500   # 8   0.0010  79% # 7   -.0003  75% # 6   -.0005  71% # 4   0.0012  63%

 1/ 4  28 .2500   # 3   0.0001  80% 7/32  0.0036  67% 7/32  0.0013  67% 7/32  -.0010  67%

 5/16  18 .3125   17/64 0.0108  65% 17/64 0.0072  65% 17/64 0.0036  65% 17/64 0.0000  65%

 5/16  24 .3125   9/32  0.0121  58% 9/32  0.0094  58% 9/32  0.0067  58% 9/32  0.0040  58%

 3/ 8  16 .3750   5/16  0.0025  77% 5/16  -.0016  77% 21/64 0.0099  58% 21/64 0.0059  58%

 3/ 8  24 .3750   11/32 0.0121  58% 11/32 0.0094  58% 11/32 0.0067  58% 11/32 0.0040  58%

 7/16  14 .4375   3/ 8  0.0117  67% 3/ 8  0.0071  67% 3/ 8  0.0025  67% 25/64 0.0134  51%

 7/16  20 .4375   25/64 0.0051  72% 25/64 0.0018  72% 25/64 -.0014  72% 13/32 0.0110  48%

 1/ 2  13 .5000   27/64 0.0018  78% 7/16  0.0124  63% 7/16  0.0074  63% 7/16  0.0025  63%

 1/ 2  20 .5000   29/64 0.0051  72% 29/64 0.0018  72% 29/64 -.0014  72% 15/32 0.0110  48%

 5/ 8  11 .6250   17/32 0.0008  79% 35/64 0.0105  66% 35/64 0.0046  66% 35/64 -.0013  66%

 5/ 8  18 .6250   37/64 0.0108  65% 37/64 0.0072  65% 37/64 0.0036  65% 37/64 0.0000  65%

 

M  2 0.40 .0787   1/16  0.0001  79% #52   0.0001  74% #51   0.0026  57% #51   0.0016  57%

M  2 0.25 .0787   #50   0.0015  68% #50   0.0008  68% #50   0.0002  68% #49   0.0026  45%

M  3 0.50 .1181   #40   0.0003  79% #39   0.0006  73% #38   0.0013  65% #38   0.0000  65%

M  3 0.35 .1181   #37   0.0002  79% #36   0.0018  65% #36   0.0009  65% #36   0.0000  65%

M  4 0.70 .1575   #30   -.0003  81% #29   0.0054  60% #29   0.0036  60% #29   0.0018  60%

M  4 0.50 .1575   #28   0.0035  66% #28   0.0022  66% #28   0.0009  66% #28   -.0004  66%

M  5 0.80 .1969   #19   0.0019  75% #19   -.0002  75% #18   0.0013  67% #18   -.0008  67%

M  5 0.50 .1969   #16   0.0006  78% #16   -.0007  78% #15   0.0010  66% #15   -.0002  66%

M  6 1.00 .2362   # 9   0.0007  79% # 8   0.0011  73% # 7   0.0006  69% 13/64 0.0001  65%

M  6 0.75 .2362   # 5   -.0000  80% # 4   0.0015  71% # 4   -.0004  71% # 3   0.0017  61%

M  7 1.00 .2756   15/64 -.0003  81% 1/ 4  0.0128  50% 1/ 4  0.0102  50% 1/ 4  0.0077  50%

M  7 0.75 .2756   1/ 4  0.0051  67% 1/ 4  0.0032  67% 1/ 4  0.0013  67% 1/ 4  -.0007  67%

M  8 1.25 .3150   17/64 0.0018  77% 17/64 -.0014  77% 9/32  0.0111  53% 9/32  0.0079  53%

M  8 1.00 .3150   9/32  0.0073  66% 9/32  0.0047  66% 9/32  0.0021  66% 9/32  -.0004  66%

M  8 0.75 .3150   19/64 0.0126  47% 19/64 0.0107  47% 19/64 0.0088  47% 19/64 0.0069  47%

M 10 1.50 .3937   11/32 0.0115  65% 11/32 0.0076  65% 11/32 0.0038  65% 11/32 -.0000  65%

M 10 1.25 .3937   11/32 0.0012  78% 11/32 -.0020  78% 23/64 0.0104  54% 23/64 0.0073  54%

M 10 1.00 .3937   23/64 0.0066  67% 23/64 0.0041  67% 23/64 0.0015  67% 23/64 -.0011  67%

M 10 0.75 .3937   3/ 8  0.0120  49% 3/ 8  0.0101  49% 3/ 8  0.0081  49% 3/ 8  0.0062  49%

M 12 1.75 .4724   13/32 0.0055  74% 13/32 0.0010  74% 27/64 0.0121  56% 27/64 0.0076  56%

M 12 1.50 .4724   27/64 0.0108  66% 27/64 0.0070  66% 27/64 0.0032  66% 27/64 -.0007  66%

M 12 1.25 .4724   27/64 0.0006  79% 7/16  0.0130  55% 7/16  0.0098  55% 7/16  0.0066  55%

M 12 1.00 .4724   7/16  0.0060  68% 7/16  0.0034  68% 7/16  0.0009  68% 7/16  -.0017  68%

 


Here are the sizes of drill required to produce the required thread. For each line the first part is the size of screw followed by the threads per inch or in metric the pitch. For example 4 40 is a size 4 screw with 40 threads per inch. While M 2 0.40 is a metric 2mm with a 0.40mm pitch, the distances between one peak to the next. Depending on what kind of material being tapped the size of hole will vary. When taping by hand use 90% to 50% and when using power tools use 80% through 50%. The most common used size drill is group 2. For sheet brass, sheet nickel, babbitt, white metal, hard rubber use group 1. For mild steel, aluminum, cast iron, and cast brass use group 2. For bronze, tool steel, drop forging, stainless steel, cast steel, nickel, and copper use group 3. This table lists the next available American drill except for the letter drills use the next larger size. Pick the group best suited for you work pick either drill listed. Note letter drills have been substituted for the next larger fractional drill; as a result the percent is lower than expected.

 

    Size   diam.              group 1           group 2           group 3

                                    /---------------------------\

                  /---------------------------\       /---------------------------\    

    4  40 .1120   #44     80%       #43     71%       #43     71%       #42     57%      

    6  32 .1380   #36     78%       7/64    70%       7/64    70%       #34     67%      

    8  32 .1640   #29     69%       #29     69%       #29     69%       #28     58%      

   10  24 .1900   #26     79%       #25     75%       #24     70%       #23     67%      

   10  32 .1900   #22     81%       #21     76%       #20     71%       #19     59%      

   12  24 .2160   11/64   81%       #16     72%       #15     67%       #15     67%      

   12  28 .2160   #15     78%       #14     73%       #13     67%       #13     67%      

 

 1/ 4  20 .2500   # 8     79%       # 7     75%       # 6     71%       # 4     63%      

 1/ 4  28 .2500   # 3     80%       7/32    67%       7/32    67%       7/32    67%      

 5/16  18 .3125   17/64   65%       17/64   65%       17/64   65%       17/64   65%       

 5/16  24 .3125   9/32    58%       9/32    58%       9/32    58%       9/32    58%      

 3/ 8  16 .3750   5/16    77%       5/16    77%       21/64   58%       21/64   58%      

 3/ 8  24 .3750   11/32   58%       11/32   58%       11/32   58%       11/32   58%      

 7/16  14 .4375   3/ 8    67%       3/ 8    67%       3/ 8    67%       25/64   51%      

 7/16  20 .4375   25/64   72%       25/64   72%       25/64   72%       13/32   48%      

 1/ 2  13 .5000   27/64   78%       7/16    63%       7/16    63%       7/16    63%      

 1/ 2  20 .5000   29/64   72%       29/64   72%       29/64   72%       15/32   48%      

 5/ 8  11 .6250   17/32   79%       35/64   66%       35/64   66%       35/64   66%      

 5/ 8  18 .6250   37/64   65%       37/64   65%       37/64   65%       37/64   65%      

 

M  2 0.40 .0787   1/16    79%       #52     74%       #51     57%       #51     57%      

M  2 0.25 .0787   #50     68%       #50     68%       #50     68%       #49     45%      

M  3 0.50 .1181   #40     79%       #39     73%       #38     65%       #38     65%      

M  3 0.35 .1181   #37     79%       #36     65%       #36     65%       #36     65%      

M  4 0.70 .1575   #30     81%       #29     60%       #29     60%       #29     60%      

M  4 0.50 .1575   #28     66%       #28     66%       #28     66%       #28     66%      

M  5 0.80 .1969   #19     75%       #19     75%       #18     67%       #18     67%      

M  5 0.50 .1969   #16     78%       #16     78%       #15     66%       #15     66%      

M  6 1.00 .2362   # 9     79%       # 8     73%       # 7     69%       13/64   65%      

M  6 0.75 .2362   # 5     80%       # 4     71%       # 4     71%       # 3     61%      

M  7 1.00 .2756   15/64   81%       1/ 4    50%       1/ 4    50%       1/ 4    50%      

M  7 0.75 .2756   1/ 4    67%       1/ 4    67%       1/ 4    67%       1/ 4    67%      

M  8 1.25 .3150   17/64   77%       17/64   77%       9/32    53%       9/32    53%      

M  8 1.00 .3150   9/32    66%       9/32    66%       9/32    66%       9/32    66%      

M  8 0.75 .3150   19/64   47%       19/64   47%       19/64   47%       19/64   47%      

M 10 1.50 .3937   11/32   65%       11/32   65%       11/32   65%       11/32   65%      

M 10 1.25 .3937   11/32   78%       11/32   78%       23/64   54%       23/64   54%      

M 10 1.00 .3937   23/64   67%       23/64   67%       23/64   67%       23/64   67%      

M 10 0.75 .3937   3/ 8    49%       3/ 8    49%       3/ 8    49%       3/ 8    49%      

M 12 1.75 .4724   13/32   74%       13/32   74%       27/64   56%       27/64   56%      

M 12 1.50 .4724   27/64   66%       27/64   66%       27/64   66%       27/64   66%      

M 12 1.25 .4724   27/64   79%       7/16    55%       7/16    55%       7/16    55%      

M 12 1.00 .4724   7/16    68%       7/16    68%       7/16    68%       7/16    68%      

 


The tap is the size and thread per inch. The drill is the recommended size to drill the hole for tapping or use the next fraction. The decimal size is the smallest and largest size of hole for hand tapping with 90% to 50% thread.

 

National                                    National

Course                                      Fine

 

   Tap     Drill   Decimal                  Tap     Drill   Decimal

   4-40    43      .083 - .096              4-48    42      .088 - .099

 

   6-32    36      .102 - .118              6-40    33      .109 - .122

 

   8-32    29      .128 - .144              8-36    29      .132 - .146

 

  10-24    25      .141 - .163             10-32    21      .154 - .170

 

  12-24    16      .167 - .189             12-28    14      .174 - .193

 

 1/4-20     7      .192 - .218            1/4-28     3      .208 - .227

 

5/16-18     F      .247 - .276           5/16-24     I      .263 - .285

 

 3/8-16     5/16   .302 - .334            3/8-24     Q      .326 - .348

 

7/16-14     U      .354 - .391           7/16-20    25/64   .379 - .405

 

 1/2-13    27/64   .410 - .450            1/2-20    29/64   .442 - .468

 

 

 

 

The tap is the size and thread per inch. The drill is the recommended size to drill the hole for tapping or use the next fraction. The decimal size is the smallest and largest size of hole for hand tapping with 90% to 50% thread.

 

National                                    National

Course                                      Fine

 

   Tap     Drill   Decimal                  Tap     Drill   Decimal

   4-40    43      .083 - .096              4-48    42      .088 - .099

   6-32    36      .102 - .118              6-40    33      .109 - .122

   8-32    29      .128 - .144              8-36    29      .132 - .146

  10-24    25      .141 - .163             10-32    21      .154 - .170

  12-24    16      .167 - .189             12-28    14      .174 - .193

 1/4-20     7      .192 - .218            1/4-28     3      .208 - .227

5/16-18     F      .247 - .276           5/16-24     I      .263 - .285

 3/8-16     5/16   .302 - .334            3/8-24     Q      .326 - .348

7/16-14     U      .354 - .391           7/16-20    25/64   .379 - .405

 1/2-13    27/64   .410 - .450            1/2-20    29/64   .442 - .468

 


 screw    size         screw    size         screw    size         screw    size

 


 # 0     .0600

 # 1     .0730

 # 2     .0860

 # 3     .0990

 # 4     .1120

 # 5     .1250

 # 6     .1380

 # 8     .1640

 #10     .1900

 #12     .2160

 #14     .2420

 1/ 4    .2500

 5/16    .3125

 3/ 8    .3750

 7/16    .4375

 1/ 2    .5000

 9/16    .5625

 5/ 8    .6250

11/16    .6875

 3/ 4    .7500

13/16    .8125

 7/ 8    .8750

15/16    .9375

 

  1.0mm  .0394

  1.5mm  .0591

  2.0mm  .0787

  2.5mm  .0984

  3.0mm  .1181

  3.5mm  .1378

  4.0mm  .1575

  4.5mm  .1772

  5.0mm  .1969

  5.5mm  .2165

  6.0mm  .2362

  7.0mm  .2756

  8.0mm  .3150

  9.0mm  .3543

 10.0mm  .3937

 11.0mm  .4331

 12.0mm  .4724

 13.0mm  .5118

 14.0mm  .5512

 15.0mm  .5906

 16.0mm  .6299

 17.0mm  .6693

 18.0mm  .7087

 20.0mm  .7874

 22.0mm  .8661

 24.0mm  .9449

  1.0mm  .0394

  1.5mm  .0591

 # 0     .0600

 # 1     .0730

  2.0mm  .0787

 # 2     .0860

  2.5mm  .0984

 # 3     .0990

 # 4     .1120

  3.0mm  .1181

 # 5     .1250

  3.5mm  .1378

 # 6     .1380

  4.0mm  .1575

 # 8     .1640

  4.5mm  .1772

 #10     .1900

  5.0mm  .1969

 #12     .2160

  5.5mm  .2165

  6.0mm  .2362

 #14     .2420

 1/ 4    .2500

  7.0mm  .2756

 5/16    .3125

  8.0mm  .3150

  9.0mm  .3543

 3/ 8    .3750

 10.0mm  .3937

 11.0mm  .4331

 7/16    .4375

 12.0mm  .4724

 1/ 2    .5000

 13.0mm  .5118

 14.0mm  .5512

 9/16    .5625

 15.0mm  .5906

 5/ 8    .6250

 16.0mm  .6299

 17.0mm  .6693

11/16    .6875

 18.0mm  .7087

 3/ 4    .7500

 20.0mm  .7874

13/16    .8125

 22.0mm  .8661

 7/ 8    .8750

15/16    .9375

 24.0mm  .9449


 

Convert metric mm to inch.  Add the column number to the number on left in mm

the body is the decimal inches converted.  2.5mm =.0984 inch.

 

      0.0    0.1    0.2    0.3    0.4    0.5    0.6    0.7    0.8    0.9

 0  .0000  .0039  .0079  .0118  .0157  .0197  .0236  .0276  .0315  .0354

 1  .0394  .0433  .0472  .0512  .0551  .0591  .0630  .0669  .0709  .0748

 2  .0787  .0827  .0866  .0906  .0945  .0984  .1024  .1063  .1102  .1142

 3  .1181  .1220  .1260  .1299  .1339  .1378  .1417  .1457  .1496  .1535

 4  .1575  .1614  .1654  .1693  .1732  .1772  .1811  .1850  .1890  .1929

 5  .1969  .2008  .2047  .2087  .2126  .2165  .2205  .2244  .2283  .2323

 6  .2362  .2402  .2441  .2480  .2520  .2559  .2598  .2638  .2677  .2717

 7  .2756  .2795  .2835  .2874  .2913  .2953  .2992  .3031  .3071  .3110

 8  .3150  .3189  .3228  .3268  .3307  .3346  .3386  .3425  .3465  .3504

 9  .3543  .3583  .3622  .3661  .3701  .3740  .3780  .3819  .3858  .3898

10  .3937  .3976  .4016  .4055  .4094  .4134  .4173  .4213  .4252  .4291

11  .4331  .4370  .4409  .4449  .4488  .4528  .4567  .4606  .4646  .4685

12  .4724  .4764  .4803  .4843  .4882  .4921  .4961  .5000  .5039  .5079

13  .5118  .5157  .5197  .5236  .5276  .5315  .5354  .5394  .5433  .5472

14  .5512  .5551  .5591  .5630  .5669  .5709  .5748  .5787  .5827  .5866

15  .5906  .5945  .5984  .6024  .6063  .6102  .6142  .6181  .6220  .6260

16  .6299  .6339  .6378  .6417  .6457  .6496  .6535  .6575  .6614  .6654

17  .6693  .6732  .6772  .6811  .6850  .6890  .6929  .6969  .7008  .7047

18  .7087  .7126  .7165  .7205  .7244  .7283  .7323  .7362  .7402  .7441

19  .7480  .7520  .7559  .7598  .7638  .7677  .7717  .7756  .7795  .7835

20  .7874  .7913  .7953  .7992  .8031  .8071  .8110  .8150  .8189  .8228

21  .8268  .8307  .8346  .8386  .8425  .8465  .8504  .8543  .8583  .8622

22  .8661  .8701  .8740  .8780  .8819  .8858  .8898  .8937  .8976  .9016

23  .9055  .9094  .9134  .9173  .9213  .9252  .9291  .9331  .9370  .9409

24  .9449  .9488  .9528  .9567  .9606  .9646  .9685  .9724  .9764  .9803

 

The following three rows are the size of wood and sheet metal screws. The first row is the size of screw followed by the diameter in 0.001 of an inch and threads per inch. Example a number 10 screw is .190 in diameter and normally has 13 threads per inch.

 

 0    1    2    3    4    5    6    7    8    9   10   11   12   14   16   18   20   24

60   73   86   99  112  125  138  151  164  177  190  203  216  242  268  294  320  372

32   28   26   24   22   20   18   16   15   14   13   12   11   10    9    8    8    7
The left column is in threads per inch. For taping by hand use 90% to 50% and for power tapping use 80% through 50%. For most common work use 75%. For sheet brass, sheet nickel, babbitt, white metal, hard rubber use 75% to 80%. For mild steel, aluminum, cast iron, and cast brass use 70% to 75%. For bronze, tool steel, drop forging, stainless steel, cast steel, nickel, and copper use 65% to 70%.  Pick a percent thread to remain and reduce screw size by the value given in table. A 10-32 has a diameter of .190 for a 75% thread subtract .0304 and arrive at .1596. A #21 drill is .159 which would be a good choice. A #20 drill is .161 would also work.

 

THREAD reduce OD of screw by this amount to obtain required percent of thread

 

tpi   100%    95%    90%    85%    80%    75%    70%    65%    60%    55%    50%  

 

12    .1083  .1028  .0974  .0920  .0866  .0812  .0758  .0704  .0649  .0595  .0541

13    .0999  .0949  .0899  .0849  .0799  .0749  .0699  .0649  .0600  .0550  .0500

14    .0928  .0881  .0835  .0789  .0742  .0696  .0649  .0603  .0557  .0510  .0464

16    .0812  .0771  .0731  .0690  .0649  .0609  .0568  .0528  .0487  .0447  .0406

18    .0722  .0686  .0649  .0613  .0577  .0541  .0505  .0469  .0433  .0397  .0361

20    .0649  .0617  .0585  .0552  .0520  .0487  .0455  .0422  .0390  .0357  .0325

24    .0541  .0514  .0487  .0460  .0433  .0406  .0379  .0352  .0325  .0298  .0271

28    .0464  .0441  .0418  .0394  .0371  .0348  .0325  .0302  .0278  .0255  .0232

32    .0406  .0386  .0365  .0345  .0325  .0304  .0284  .0264  .0244  .0223  .0203

36    .0361  .0343  .0325  .0307  .0289  .0271  .0253  .0235  .0217  .0198  .0180

40    .0325  .0309  .0292  .0276  .0260  .0244  .0227  .0211  .0195  .0179  .0162

44    .0295  .0280  .0266  .0251  .0236  .0221  .0207  .0192  .0177  .0162  .0148

48    .0271  .0257  .0244  .0230  .0217  .0203  .0189  .0176  .0162  .0149  .0135

56    .0232  .0220  .0209  .0197  .0186  .0174  .0162  .0151  .0139  .0128  .0116

64    .0203  .0193  .0183  .0173  .0162  .0152  .0142  .0132  .0122  .0112  .0101

72    .0180  .0171  .0162  .0153  .0144  .0135  .0126  .0117  .0108  .0099  .0090

80    .0162  .0154  .0146  .0138  .0130  .0122  .0114  .0106  .0097  .0089  .0081

 

 

 

These are the metric threads mm between threads, thread depth are in inches.

 

pitch  100%    95%    90%    85%    80%    75%    70%    65%    60%    55%    50%  

 

3.00  .1534  .1458  .1381  .1304  .1227  .1151  .1074  .0997  .0921  .0844  .0767

2.50  .1279  .1215  .1151  .1087  .1023  .0959  .0895  .0831  .0767  .0703  .0639

2.00  .1023  .0972  .0921  .0869  .0818  .0767  .0716  .0665  .0614  .0563  .0511

1.75  .0895  .0850  .0806  .0761  .0716  .0671  .0627  .0582  .0537  .0492  .0448

1.50  .0767  .0729  .0690  .0652  .0614  .0575  .0537  .0499  .0460  .0422  .0384

1.25  .0639  .0607  .0575  .0543  .0511  .0479  .0448  .0416  .0384  .0352  .0320

1.00  .0511  .0486  .0460  .0435  .0409  .0384  .0358  .0332  .0307  .0281  .0256

 .90  .0460  .0437  .0414  .0391  .0368  .0345  .0322  .0299  .0276  .0253  .0230

 .80  .0409  .0389  .0368  .0348  .0327  .0307  .0286  .0266  .0245  .0225  .0205

 .75  .0384  .0364  .0345  .0326  .0307  .0288  .0269  .0249  .0230  .0211  .0192

 .70  .0358  .0340  .0322  .0304  .0286  .0269  .0251  .0233  .0215  .0197  .0179

 .65  .0332  .0316  .0299  .0283  .0266  .0249  .0233  .0216  .0199  .0183  .0166

 .60  .0307  .0292  .0276  .0261  .0245  .0230  .0215  .0199  .0184  .0169  .0153

 .55  .0281  .0267  .0253  .0239  .0225  .0211  .0197  .0183  .0169  .0155  .0141

 .50  .0256  .0243  .0230  .0217  .0205  .0192  .0179  .0166  .0153  .0141  .0128

 .45  .0230  .0219  .0207  .0196  .0184  .0173  .0161  .0150  .0138  .0127  .0115

 .40  .0205  .0194  .0184  .0174  .0164  .0153  .0143  .0133  .0123  .0113  .0102

 .35  .0179  .0170  .0161  .0152  .0143  .0134  .0125  .0116  .0107  .0098  .0090

 .30  .0153  .0146  .0138  .0130  .0123  .0115  .0107  .0100  .0092  .0084  .0077

 .25  .0128  .0121  .0115  .0109  .0102  .0096  .0090  .0083  .0077  .0070  .0064

 .20  .0102  .0097  .0092  .0087  .0082  .0077  .0072  .0066  .0061  .0056  .0051

 

 
   drill    size     drill   size     drill    size     drill   size    drill     size

 


 #97     .0059

 #96     .0063

 #95     .0067

 #94     .0071

 #93     .0075

 #92     .0079

 #91     .0083

 #90     .0087

 #89     .0091

 #88     .0094

 #87     .0098

 #86     .0102

 #85     .0110

 #84     .0114

 #83     .0122

 #82     .0126

 #81     .0130

 #80     .0135

 #79     .0145

 #78     .0160

 #77     .0180

 #76     .0200

 #75     .0210

 #74     .0225

 #73     .0240

 #72     .0250

 #71     .0260

 #70     .0280

 #69     .0292

 #68     .0310

 #67     .0320

 #66     .0330

 #65     .0350

 #64     .0360

 #63     .0370

 #62     .0380

 #61     .0390

 1.00mm  .0394

 #60     .0400

 #59     .0410

 #58     .0420

 #57     .0430

 1.10mm  .0433

 #56     .0465

 1.20mm  .0472

 1.30mm  .0512

 #55     .0520

 #54     .0550

 1.40mm  .0551

 1.50mm  .0591

 #53     .0595

 1/16    .0625

 1.60mm  .0630

 #52     .0635

 1.70mm  .0669

 #51     .0670

 #50     .0700

 1.80mm  .0709

 #49     .0730

 1.90mm  .0748

 #48     .0760

 5/64    .0781

 #47     .0785

 2.00mm  .0787

 #46     .0810

 #45     .0820

 2.10mm  .0827

 #44     .0860

 2.20mm  .0866

 #43     .0890

 2.30mm  .0906

 #42     .0935

 3/32    .0938

 2.40mm  .0945

 #41     .0960

 #40     .0980

 2.50mm  .0984

 #39     .0995

 #38     .1015

 2.60mm  .1024

 #37     .1040

 2.70mm  .1063

 #36     .1065

 7/64    .1094

 #35     .1100

 2.80mm  .1102

 #34     .1110

 #33     .1130

 2.90mm  .1142

 #32     .1160

 3.00mm  .1181

 #31     .1200

 3.10mm  .1220

 1/ 8    .1250

 3.20mm  .1260

 #30     .1285

 3.30mm  .1299

 3.40mm  .1339

 #29     .1360

 3.50mm  .1378

 #28     .1405

 9/64    .1406

 3.60mm  .1417

 #27     .1440

 3.70mm  .1457

 #26     .1470

 #25     .1495

 3.80mm  .1496

 #24     .1520

 3.90mm  .1535

 #23     .1540

 5/32    .1563

 #22     .1570

 4.00mm  .1575

 #21     .1590

 #20     .1610

 4.10mm  .1614

 4.20mm  .1654

 #19     .1660

 4.30mm  .1693

 #18     .1695

11/64    .1719

 #17     .1730

 4.40mm  .1732

 #16     .1770

 4.50mm  .1772

 #15     .1800

 4.60mm  .1811

 #14     .1820

 #13     .1850

 4.70mm  .1850

 3/16    .1875

 4.80mm  .1890

 #12     .1890

 #11     .1910

 4.90mm  .1929

 #10     .1935

 # 9     .1960

 5.00mm  .1969

 # 8     .1990

 5.10mm  .2008

 # 7     .2010

13/64    .2031

 # 6     .2040

 5.20mm  .2047

 # 5     .2055

 5.30mm  .2087

 # 4     .2090

 5.40mm  .2126

 # 3     .2130

 5.50mm  .2165

 7/32    .2188

 5.60mm  .2205

 # 2     .2210

 5.70mm  .2244

 # 1     .2280

 5.80mm  .2283

 5.90mm  .2323

   A     .2340

15/64    .2344

 6.00mm  .2362

   B     .2380

 6.10mm  .2402

   C     .2420

 6.20mm  .2441

   D     .2460

 6.30mm  .2480

 1/ 4    .2500

   E     .2500

 6.40mm  .2520

 6.50mm  .2559

   F     .2570

 6.60mm  .2598

   G     .2610

 6.70mm  .2638

17/64    .2656

   H     .2660

 6.80mm  .2677

 6.90mm  .2717

   I     .2720

 7.00mm  .2756

   J     .2770

 7.10mm  .2795

   K     .2810

 9/32    .2813

 7.20mm  .2835

 7.30mm  .2874

   L     .2900

 7.40mm  .2913

   M     .2950

 7.50mm  .2953

19/64    .2969

 7.60mm  .2992

   N     .3020

 7.70mm  .3031

 7.80mm  .3071

 7.90mm  .3110

 5/16    .3125

 8.00mm  .3150

   O     .3160

 8.10mm  .3189

 8.20mm  .3228

   P     .3230

 8.30mm  .3268

21/64    .3281

 8.40mm  .3307

   Q     .3320

 8.50mm  .3346

 8.60mm  .3386

   R     .3390

 8.70mm  .3425

11/32    .3438

 8.80mm  .3465

   S     .3480

 8.90mm  .3504

 9.00mm  .3543

   T     .3580

 9.10mm  .3583

23/64    .3594

 9.20mm  .3622

 9.30mm  .3661

   U     .3680

 9.40mm  .3701

 9.50mm  .3740

 3/ 8    .3750

   V     .3770

 9.60mm  .3780

 9.70mm  .3819

 9.80mm  .3858

   W     .3860

 9.90mm  .3898

25/64    .3906

10.00mm  .3937

   X     .3970

10.10mm  .3976

10.20mm  .4016

   Y     .4040

10.30mm  .4055

13/32    .4063

10.40mm  .4094

   Z     .4130

10.50mm  .4134

10.60mm  .4173

10.70mm  .4213

27/64    .4219

10.80mm  .4252

10.90mm  .4291

11.00mm  .4331

11.10mm  .4370

 7/16    .4375

11.20mm  .4409

11.30mm  .4449

11.40mm  .4488

11.50mm  .4528

29/64    .4531

11.60mm  .4567

11.70mm  .4606

11.80mm  .4646

11.90mm  .4685

15/32    .4688

12.00mm  .4724

12.10mm  .4764

12.20mm  .4803

12.30mm  .4843

31/64    .4844

12.40mm  .4882

12.50mm  .4921

12.60mm  .4961

 1/ 2    .5000

12.70mm  .5000

12.80mm  .5039

12.90mm  .5079

13.00mm  .5118

13.10mm  .5157

13.20mm  .5197

13.30mm  .5236

13.40mm  .5276

13.50mm  .5315

13.60mm  .5354

13.80mm  .5433

14.00mm  .5512

14.20mm  .5591

 9/16    .5625

14.40mm  .5669

14.50mm  .5709

14.60mm  .5748

14.80mm  .5827

15.00mm  .5906

 5/ 8    .6250

16.00mm  .6299

17.00mm  .6693

11/16    .6875

18.00mm  .7087

19.00mm  .7480

 3/ 4    .7500

20.00mm  .7874

13/16    .8125

21.00mm  .8268

22.00mm  .8661

 7/ 8    .8750

23.00mm  .9055

15/16    .9375

24.00mm  .9449

25.00mm  .9843



This table is for the most commonly used screw sizes. For taping by hand use 90% to 50% and for power tapping use 80% through 50%. For most common work use 75%. For sheet brass, sheet nickel, babbitt, white metal, hard rubber use 75% to 80%. For mild steel, aluminum, cast iron, and cast brass use 70% to 75%. For bronze, tool steel, drop forging, stainless steel, cast steel, nickel, and copper use 65% to 70%. In the table below the “screw” is the type of screw. The “size” is the outside diameter of screw. The 100% to 50% are the percent of threads remaining after tapping the hole drilled out.

 

    screw    size   100%   95%   90%   85%   80%   75%   70%   65%   60%   55%   50%

     4  40  .1120  .0795 .0811 .0828 .0844 .0860 .0876 .0893 .0909 .0925 .0941 .0958

     6  32  .1380  .0974 .0994 .1015 .1035 .1055 .1076 .1096 .1116 .1136 .1157 .1177

     8  32  .1640  .1234 .1254 .1275 .1295 .1315 .1336 .1356 .1376 .1396 .1417 .1437

    10  24  .1900  .1359 .1386 .1413 .1440 .1467 .1494 .1521 .1548 .1575 .1602 .1629

    10  32  .1900  .1494 .1514 .1535 .1555 .1575 .1596 .1616 .1636 .1656 .1677 .1697

    12  24  .2160  .1619 .1646 .1673 .1700 .1727 .1754 .1781 .1808 .1835 .1862 .1889

 

   1/4  20  .2500  .1850 .1883 .1915 .1948 .1980 .2013 .2045 .2078 .2110 .2143 .2175

   1/4  28  .2500  .2036 .2059 .2082 .2106 .2129 .2152 .2175 .2198 .2222 .2245 .2268

   5/16 18  .3125  .2403 .2439 .2475 .2512 .2548 .2584 .2620 .2656 .2692 .2728 .2764

   5/16 24  .3125  .2584 .2611 .2638 .2665 .2692 .2719 .2746 .2773 .2800 .2827 .2854

   3/8  16  .3750  .2938 .2979 .3019 .3060 .3100 .3141 .3182 .3222 .3263 .3303 .3344

   3/8  24  .3750  .3209 .3236 .3263 .3290 .3317 .3344 .3371 .3398 .3425 .3452 .3479

   7/16 14  .4375  .3447 .3494 .3540 .3586 .3633 .3679 .3725 .3772 .3818 .3865 .3911

   7/16 20  .4375  .3725 .3758 .3790 .3823 .3855 .3888 .3920 .3953 .3985 .4018 .4050

   1/2  13  .5000  .4001 .4051 .4101 .4151 .4201 .4251 .4301 .4350 .4400 .4450 .4500

   1/2  20  .5000  .4350 .4383 .4415 .4448 .4480 .4513 .4545 .4578 .4610 .4643 .4675

 

M  3  0.50  .1181  .0925 .0938 .0951 .0964 .0977 .0989 .1002 .1015 .1028 .1040 .1053

M  4  0.70  .1575  .1217 .1235 .1253 .1271 .1288 .1306 .1324 .1342 .1360 .1378 .1396

M  5  0.80  .1969  .1559 .1580 .1600 .1621 .1641 .1662 .1682 .1703 .1723 .1743 .1764

M  5  0.90  .1969  .1508 .1531 .1554 .1577 .1600 .1623 .1646 .1669 .1692 .1715 .1738

M  6  0.75  .2362  .1979 .1998 .2017 .2036 .2055 .2075 .2094 .2113 .2132 .2151 .2170

M  6  1.00  .2362  .1851 .1876 .1902 .1927 .1953 .1979 .2004 .2030 .2055 .2081 .2106

M  8  1.00  .3150  .2638 .2664 .2689 .2715 .2740 .2766 .2792 .2817 .2843 .2868 .2894

M  8  1.25  .3150  .2510 .2542 .2574 .2606 .2638 .2670 .2702 .2734 .2766 .2798 .2830

M 10  1.25  .3937  .3298 .3330 .3362 .3394 .3426 .3458 .3490 .3521 .3553 .3585 .3617

M 10  1.50  .3937  .3170 .3208 .3247 .3285 .3323 .3362 .3400 .3438 .3477 .3515 .3553

M 12  1.50  .4724  .3957 .3996 .4034 .4072 .4111 .4149 .4187 .4226 .4264 .4302 .4341

M 12  1.75  .4724  .3829 .3874 .3919 .3964 .4008 .4053 .4098 .4143 .4187 .4232 .4277

 

drill  size     drill   size      drill   size     drill   size      drill   size


 #60  .0400

 #59  .0410

 #58  .0420

 #57  .0430

 #56  .0465

 #55  .0520

 #54  .0550

 #53  .0595

 1/16 .0625

 #52  .0635

 #51  .0670

 #50  .0700

 #49  .0730

 #48  .0760

 5/64 .0781

 #47  .0785

 #46  .0810

 #45  .0820

 #44  .0860

 #43  .0890

 #42  .0935

 3/32 .0938

 #41  .0960

 #40  .0980

 #39  .0995

 #38  .1015

 #37  .1040

 #36  .1065

 7/64 .1094

 #35  .1100

 #34  .1110

 #33  .1130

 #32  .1160

 #31  .1200

 1/ 8 .1250

 #30  .1285

 #29  .1360

 #28  .1405

 9/64 .1406

 #27  .1440

 #26  .1470

 #25  .1495

 #24  .1520

 #23  .1540

 5/32 .1563

 #22  .1570

 #21  .1590

 #20  .1610

 #19  .1660

 #18  .1695

11/64 .1719

 #17  .1730

 #16  .1770

 #15  .1800

 #14  .1820

 #13  .1850

 3/16 .1875

 #12  .1890

 #11  .1910

 #10  .1935

 # 9  .1960

 # 8  .1990

 # 7  .2010

13/64 .2031

 # 6  .2040

 # 5  .2055

 # 4  .2090

 # 3  .2130

 7/32 .2188

 # 2  .2210

 # 1  .2280

   A  .2340

15/64 .2344

   B  .2380

   C  .2420

   D  .2460

 1/ 4 .2500

   E  .2500

   F  .2570

   G  .2610

17/64 .2656

   H  .2660

   I  .2720

   J  .2770

   K  .2810

 9/32 .2813

   L  .2900

   M  .2950

19/64 .2969

   N  .3020

 5/16 .3125

   O  .3160

   P  .3230

21/64 .3281

   Q  .3320

   R  .3390

11/32 .3438

   S  .3480

   T  .3580

23/64 .3594

   U  .3680

 3/ 8 .3750

   V  .3770

   W  .3860

25/64 .3906

   X  .3970

   Y  .4040

13/32 .4063

   Z  .4130

27/64 .4219

 7/16 .4375

29/64 .4531

15/32 .4688

31/64 .4844

 1/ 2 .5000




107         0.0019
106         0.0023
105         0.0027
104         0.0031
103         0.0035
102         0.0039
101         0.0043
100         0.0047
99          0.0051
98          0.0055
97          0.0059
96          0.0063
95          0.0067
94          0.0071
93          0.0075
92          0.0079
.2mm        0.0079
91          0.0083
90          0.0087
.22mm       0.0087
89          0.0091
88          0.0095
.25mm       0.0098
87          0.0100
86          0.0105
85          0.0110
.28mm       0.0110
84          0.0115
.3mm        0.0118
83          0.0120
82          0.0125
.32mm       0.0126
81          0.0130
80          0.0135
.35mm       0.0138
79          0.0145
1/64        0.0156
.4mm        0.0157
78          0.0160
.45mm       0.0177
77          0.0180
.5mm        0.0197
76          0.0200
75          0.0210
.55mm       0.0217
74          0.0225
.6mm        0.0236
73          0.0240
72          0.0250
.65mm       0.0256
71          0.0260
.7mm        0.0276
70          0.0280
69          0.0292
.75mm       0.0295
68          0.0310
1/32        0.0312
.8mm        0.0315
67          0.0320
66          0.0330
.85mm       0.0335
65          0.0350
.9mm        0.0354
64          0.0360
63          0.0370
.95mm       0.0374
62          0.0380
61          0.0390
1mm         0.0394
60          0.0400
59          0.0410
1.05mm      0.0413
58          0.0420
57          0.0430
1.1mm       0.0433
1.15mm      0.0453
56          0.0465
3/64        0.0469
1.2mm       0.0472
1.25mm      0.0492
1.3mm       0.0512
55          0.0520
1.35mm      0.0531
54          0.0550
1.4mm       0.0551
1.45mm      0.0571
1.5mm       0.0591
53          0.0595
1.55mm      0.0610
1/16        0.0625
52          0.0635
1.65mm      0.0650
1.7mm       0.0669
51          0.0670
1.75mm      0.0689
50          0.0700
1.8mm       0.0709
1.85mm      0.0728
49          0.0730
1.9mm       0.0748
48          0.0760
1.95mm      0.0768
5/64        0.0781
2mm         0.0787
2.05mm      0.0807
47          0.0785
46          0.0810
45          0.0820
2.1mm       0.0827
2.15mm      0.0846
44          0.0860
2.2mm       0.0866
2.25mm      0.0886
43          0.0890
2.3mm       0.0906
2.35mm      0.0925
42          0.0935
3/32        0.0938
2.4mm       0.0945
41          0.0960
2.45mm      0.0965
40          0.0980
2.5mm       0.0984
39          0.0995
38          0.1015
2.6mm       0.1024
37          0.1040
2.7mm       0.1063
36          0.1065
2.75mm      0.1083
7/64        0.1094
35          0.1100
2.8mm       0.1102
34          0.1110
33          0.1130
2.9mm       0.1142
32          0.1160
3mm         0.1181
31          0.1200
3.1mm       0.1181
1/8         0.1250
30          0.1285
3.3mm       0.1299
3.4mm       0.1339
29          0.1360
3.5mm       0.1378
28          0.1405
9/64        0.1406
3.6mm       0.1417
27          0.1440
3.7mm       0.1457
26          0.1470
3.75mm      0.1476
25          0.1495
3.8mm       0.1535
24          0.1520
3.9mm       0.1535
23          0.1540
5/32        0.1562
22          0.1570
4mm         0.1575
21          0.1590
20          0.1610
4.1mm       0.1614
4.2mm       0.1654
19          0.1660
4.25mm      0.1673
4.3mm       0.1693
18          0.1695
11/64       0.1719
17          0.1730
4.4mm       0.1732
16          0.1770
4.5mm       0.1772
15          0.1800
4.6mm       0.1811
14          0.1820
13          0.1850
4.7mm       0.1850
4.75mm      0.1870
3/16        0.1875
4.8mm       0.1890
12          0.1890
11          0.1910
4.9mm       0.1929
10          0.1935
9           0.1960
5.mm        0.1969
8           0.1990
5.1mm       0.2008
7           0.2010
13/64       0.2031
6           0.2040
5.2mm       0.2047
5           0.2055
5.25mm      0.2067
5.3mm       0.2087
4           0.2090
5.4mm       0.2126
3           0.2130
5.5mm       0.2165
7/32        0.2188
5.6mm       0.2205
2           0.2211
5.7mm       0.2244
5.75mm      0.2264
1           0.2280
5.8mm       0.2283
5.9mm       0.2323
A           0.2340
15/64       0.2344
6mm         0.2362
B           0.2380
6.1mm       0.2402
C           0.2420
6.2mm       0.2441
D           0.2460
6.25mm      0.2461
6.3mm       0.2480
1/4         0.2500
E           0.2500
6.4mm       0.2520
6.5mm       0.2559
F           0.2570
6.6mm       0.2598
G           0.2610
6.7mm       0.2638
17/64       0.2656
6.75mm      0.2657
H           0.2660
6.8mm       0.2677
6.9mm       0.2717
I           0.2720
7mm         0.2756
J           0.2770
7.1mm       0.2795
K           0.2810
9/32        0.2812
7.2mm       0.2835
7.25mm      0.2854
7.3mm       0.2874
L           0.2900
7.4mm       0.2913
M           0.2950
7.5mm       0.2953
19/64       0.2969
7.6mm       0.2992
N           0.3020
7.7mm       0.3031
7.75mm      0.3051
7.8mm       0.3071
7.9mm       0.3110
5/16        0.3125
8mm         0.3150
O           0.3160
8.1mm       0.3189
8.2mm       0.3228
P           0.3230
8.25mm      0.3248
8.3mm       0.3268
21/64       0.3281
8.4mm       0.3307
Q           0.3320
8.5mm       0.3346
8.6mm       0.3386
R           0.3390
8.7mm       0.3425
11/32       0.3438
8.75mm      0.3445
8.8mm       0.3465
S           0.3480
8.9mm       0.3504
9mm         0.3543
T           0.3580
9.1mm       0.3583
23/64       0.3594
9.2mm       0.3622
9.25mm      0.3642
9.3mm       0.3661
U           0.3680
9.4mm       0.3701
9.5mm       0.3740
3/8         0.3750
V           0.3770
9.6mm       0.3780
9.7mm       0.3819
9.75mm      0.3839
9.8mm       0.3858
W           0.3860
9.9mm       0.3898
25/64       0.3906
10mm        0.3937
X           0.3970
Y           0.4040
13/32       0.4062
Z           0.4130
10.5mm      0.4134
27/64       0.4219
11mm        0.4331
7/16        0.4375
11.5mm      0.4528
29/64       0.4531
15/32       0.4688
12mm        0.4724
31/64       0.4844
1/2         0.5000

13mm        0.5118

33/64       0.5156

17/32       0.5312

13.5mm      0.5315

35/64       0.5469

14mm        0.5512

9/16        0.5625

14.5mm      0.5709

37/64       0.5781

15mm        0.5906

19/32       0.5938

39/64       0.6094

15.5mm      0.6102

5/8         0.6250

16mm        0.6299

41/64       0.6406

16.5mm      0.6496

21/32       0.6562

17mm        0.6693

43/64       0.6719

11/16       0.6875

17.5mm      0.6890

45/64       0.7031

18mm        0.7087

23/32       0.7188

18.5mm      0.7283

47/64       0.7344

19mm        0.7480

3/4         0.7500

49/64       0.7656

19.5mm      0.7677

25/32       0.7812

20mm        0.7874

51/64       0.7969

20.5mm      0.8071

13/16       0.8125

21mm        0.8268

53/64       0.8281

27/32       0.8438

21.5mm      0.8465

55/64       0.8594

22mm        0.8661

7/8         0.8750

22.5mm      0.8858

57/64       0.8906

23mm        0.9055

29/32       0.9062

59/64       0.9219

23.5mm      0.9252

15/16       0.9375

24mm        0.9449

61/64       0.9531

24.5mm      0.9646

31/32       0.9688

25mm        0.9843

63/64       0.9844

1           1.0000