Specifications of International Thread Standards

Fractional-inch drill bit sizes, ANSI B94.11M-1979

No. /
Letter
Decimal
Inch
mmNo. /
Letter
Decimal
Inch
mmNo. /
Letter
Decimal
Inch
mm
800.01350.3431/80.12503.175O0.31608.026
790.01450.368300.12853.264P0.32308.204
1/640.01560.397290.13603.45421/640.32818.334
780.01600.406280.14053.569Q0.33208.433
770.01800.4579/640.14063.572R0.33908.611
760.02000.508270.14403.65811/320.34378.731
750.02100.533260.14703.734S0.34808.839
740.02250.572250.14953.797T0.35809.093
730.02400.610240.15203.86123/640.35949.128
720.02500.635230.15403.912U0.36809.347
710.02600.6605/320.15623.9693/80.37509.525
700.02800.711220.15703.988V0.37709.576
690.02920.742210.15904.039W0.38609.804
680.03100.787200.16104.08925/640.39069.922
1/320.03130.794190.16604.216X0.397010.084
670.03200.813180.16954.305Y0.404010.261
660.03300.83811/640.17194.36613/320.406210.319
650.03500.889170.17304.394Z0.413010.490
640.03600.914160.17704.49627/640.421910.716
630.03700.940150.18004.5727/160.437511.113
620.03800.965140.18204.62329/640.453111.509
610.03900.991130.18504.69915/320.468711.906
600.04001.0163/160.18754.76331/640.484412.303
590.04101.041120.18904.8011/20.500012.700
580.04201.067110.19104.85133/640.515613.295
570.04301.092100.19354.91517/320.531213.494
560.04651.18190.19604.97835/640.546913.891
3/640.04691.19180.19905.0559/160.562514.288
550.05201.32170.20105.10537/640.578114.684
540.05501.39713/640.20315.15919/320.593715.081
530.05951.51160.20405.18239/640.609415.478
1/160.06251.58850.20555.2205/80.625015.875
520.06351.61340.20905.30941/640.640616.272
510.06701.70230.21305.41021/320.656216.669
500.07001.7787/320.21875.55643/640.671917.264
490.07301.85420.22105.61311/160.687517.463
480.07601.93010.22805.79145/640.703117.859
5/640.07811.984A0.23405.94423/320.718718.256
470.07851.99415/640.23446.75447/640.734418.653
460.08102.057B0.23806.0453/40.750019.050
450.08202.083C0.24206.14749/640.765619.447
440.08602.184D0.24606.24825/320.781219.844
430.08902.261E0.25006.35051/640.796920.241
420.09352.3751/40.25006.35013/160.812520.638
3/320.09372.381F0.25706.52853/640.828121.034
410.09602.438G0.26106.62927/320.843721.431
400.09802.48917/640.26566.74755/640.859421.828
390.09952.527H0.26606.7567/80.875022.225
380.10152.578I0.27206.90957/640.890622.820
370.10402.642J0.27707.03629/320.906223.019
360.10652.705K0.28117.13759/640.921923.416
7/640.10932.7789/320.28127.14415/160.937523.813
350.10152.794L0.27207.36657/640.890622.820
340.11102.819M0.29507.49331/320.968724.606
330.11302.87019/640.29687.54163/640.984425.003
320.11602.946N0.30207.67111.00025.400
310.12003.0485/160.31257.937---