DRILL BIBLE
TAP DRILL QUICK REFERENCE CHART
| THREAD SIZE | 75% TAP DRILL (Soft Materials) |
50% TAP DRILL (Hard Materials) |
CLOSE FIT Clearance |
FREE FIT Clearance |
|---|---|---|---|---|
| #0-80 | 3/64" (0.0469) | #55 (0.0520) | #52 (0.0635) | #50 (0.0700) |
| #1-64 | #53 (0.0595) | 1/16" (0.0625) | #48 (0.0760) | #46 (0.0810) |
| #2-56 | #50 (0.0700) | #49 (0.0730) | #43 (0.0890) | #41 (0.0960) |
| #3-48 | #47 (0.0785) | #44 (0.0860) | #37 (0.1040) | #35 (0.1100) |
| #4-40 | #43 (0.0890) | #41 (0.0960) | #32 (0.1160) | #30 (0.1285) |
| #5-40 | #39 (0.0995) | #37 (0.1040) | #30 (0.1285) | #29 (0.1360) |
| #6-32 | #36 (0.1065) | #33 (0.1130) | #27 (0.1440) | #25 (0.1495) |
| #8-32 | #29 (0.1360) | #27 (0.1440) | #18 (0.1695) | #16 (0.1770) |
| #10-24 | #25 (0.1495) | #21 (0.1590) | #9 (0.1960) | #7 (0.2010) |
| #12-24 | #16 (0.1770) | #13 (0.1850) | #2 (0.2210) | 7/32" (0.2188) |
| 1/4-20 | #7 (0.2010) | #5 (0.2055) | 17/64" (0.2656) | 9/32" (0.2812) |
| 1/4-28 | #3 (0.2130) | #1 (0.2280) | 17/64" (0.2656) | 9/32" (0.2812) |
| 5/16-18 | F (0.2570) | H (0.2660) | 21/64" (0.3281) | 11/32" (0.3438) |
| 5/16-24 | I (0.2720) | J (0.2770) | 21/64" (0.3281) | 11/32" (0.3438) |
| 3/8-16 | 5/16" (0.3125) | Q (0.3320) | 25/64" (0.3906) | 13/32" (0.4062) |
| 3/8-24 | Q (0.3320) | S (0.3480) | 25/64" (0.3906) | 13/32" (0.4062) |
| 7/16-14 | U (0.3680) | X (0.3970) | 29/64" (0.4531) | 15/32" (0.4688) |
| 7/16-20 | W (0.3860) | 25/64" (0.3906) | 29/64" (0.4531) | 15/32" (0.4688) |
| 1/2-13 | 27/64" (0.4219) | 29/64" (0.4531) | 33/64" (0.5156) | 17/32" (0.5312) |
| 1/2-20 | 29/64" (0.4531) | 15/32" (0.4688) | 33/64" (0.5156) | 17/32" (0.5312) |
| 9/16-12 | 31/64" (0.4844) | 33/64" (0.5156) | 37/64" (0.5781) | 19/32" (0.5938) |
| 9/16-18 | 33/64" (0.5156) | 17/32" (0.5312) | 37/64" (0.5781) | 19/32" (0.5938) |
| 5/8-11 | 17/32" (0.5312) | 9/16" (0.5625) | 41/64" (0.6406) | 21/32" (0.6562) |
| 5/8-18 | 37/64" (0.5781) | 19/32" (0.5938) | 41/64" (0.6406) | 21/32" (0.6562) |
| 3/4-10 | 21/32" (0.6562) | 11/16" (0.6875) | 49/64" (0.7656) | 25/32" (0.7812) |
| 3/4-16 | 11/16" (0.6875) | 45/64" (0.7031) | 49/64" (0.7656) | 25/32" (0.7812) |