Tap and Drill Chart

Screw Size Major Diameter Minor Diameter Drill Size Decimal Equivalent
1/4-280.25"0.2062"10.228"
1/4-320.25"0.2117"10.228"
12-320.216"0.1777"90.196"
12-280.216"0.1722"100.1935"
12-240.216"0.1649"120.189"
10-320.19"0.1517"180.1695"
10-240.19"0.1389"200.161"
8-360.164"0.1299"260.147"
8-320.164"0.1257"270.144"
6-400.138"0.1073"310.12"
6-320.138"0.0997"320.116"
5-440.125"0.0971"350.11"
4-480.112"0.0864"400.098"
4-400.112"0.0813"410.096"
3-560.099"0.0771"430.089"
3-480.099"0.0734"440.086"
2-640.086"0.0668"480.076"
2-560.086"0.0641"490.073"
1-720.073"0.056"520.0635"
0-800.06"0.0447"550.052"
5/8-110.625"0.5135"426290.5625"
1-640.073"0.0538"1/160.0625"
3/4-100.75"0.6273"11/160.6875"
7/16-200.4375"0.3762"13/320.4062"
1/2-200.5"0.4387"15/320.4688"
1/2-280.5"0.4562"15/320.4688"
9/16-180.5625"0.4943"17/320.5312"
9/16-240.5625"0.5114"17/320.5312"
5/8-180.625"0.5568"19/320.5938"
5/8-240.625"0.5739"19/320.5938"
11/16-240.6875"0.6364"21/320.6562"
3/4-200.75"0.6887"23/320.7188"
13/16-200.8125"0.7512"25/320.7812"
7/16-140.4375"0.3499"25/640.3906"
7/8-200.875"0.8137"27/320.8438"
15/16-200.9375"0.8762"29/320.9062"
1/2-130.5"0.4056"29/640.4531"
1-201"0.9387"31/320.9688"
9/16-120.5625"0.4603"33/640.5156"
3/4-160.75"0.6733"45/640.7031"
7/8-90.875"0.7387"51/640.7969"
7/8-140.875"0.7874"53/640.8281"
1-81"0.8466"59/640.9219"
1-121"0.8978"61/640.9531"
1/4-200.25"0.1887"7/320.2188"
5-400.125"0.0943"7/640.1094"
5/16-240.3125"0.2614"9/320.2812"
5/16-180.3125"0.2443"J0.277"
5/16-320.3125"0.2742"L0.29"
3/8-160.375"0.2983"Q0.332"
3/8-240.375"0.3239"S0.348"
3/8-320.375"0.3367"T0.358"
7/16-280.4375"0.3937"Z0.413"