| American Standard Thread | ISO Metric Thread | ||
|---|---|---|---|
| Thread Size | Tap Drill Size (in.) | Thread Size | Tap Drill Size (mm) |
| 0-80 | 3/64 | M1 x 0.25 | 0.75 |
| 1-64 | #53 | M1.1 x 0.25 | 0.85 |
| 1-72 | #53 | M1.2 x 0.25 | 0.95 |
| 2-56 | #51 | M1.4 x 0.3 | 1.10 |
| 2-64 | #50 | M1.6 x 0.35 | 1.25 |
| 3-48 | 5/64 | M1.8 x 0.35 | 1.45 |
| 3-56 | #46 | M2 x 0.4 | 1.60 |
| 4-40 | #43 | M2.2 x 0.45 | 1.75 |
| 4-48 | #42 | M2.5 x 0.45 | 2.05 |
| 5-40 | #39 | M3 x 0.5 | 2.50 |
| 5-44 | #37 | M3.5 x 0.6 | 2.90 |
| 6-32 | #36 | M4 x 0.7 | 3.30 |
| 6-40 | #33 | M4.5 x 0.75 | 3.70 |
| 8-32 | #29 | M5 x 0.8 | 4.20 |
| 8-36 | #29 | M6 x 1 | 5.00 |
| 10-24 | #25 | M7 x 1 | 6.00 |
| 10-32 | #21 | M8 x 1.25 | 6.80 |
| 12-24 | #17 | M9 x 1.25 | 7.80 |
| 12-28 | #15 | M10 x 1.5 | 8.50 |
| 1/4-20 | #7 | M11 x 1.5 | 9.50 |
| 1/4-28 | #3 | M12 x 1.75 | 10.20 |
| 5/16-18 | F | M14 x 2 | 12.00 |
| 5/16-24 | I | M16 x 2 | 14.00 |
| 3/8-16 | 5/16 | M18 x 2.5 | 15.50 |
| 3/8-24 | Q | M20 x 2.5 | 17.50 |
| 7/16-14 | U | M22 x 2.5 | 19.50 |
| 7/16-20 | W | M24 x 3 | 21.00 |
| 1/2-13 | 27/64 | M27 x 3 | 24.00 |
| 1/2-20 | 29/64 | M30 x 3.5 | 26.50 |
| 9/16-12 | 31/64 | M33 x 3.5 | 29.50 |
| 9/16-18 | 33/64 | M36 x 4 | 32.00 |
| 5/8-11 | 17/32 | M39 x 4 | 35.00 |
| 5/8-18 | 37/64 | M42 x 4.5 | 37.50 |
| 3/4-10 | 21/32 | M45 x 4.5 | 40.50 |
| 3/4-16 | 11/16 | M48 x 5 | 43.00 |
| 7/8-9 | 49/64 | M52 x 5 | 47.00 |
| 7/8-14 | 13/16 | M56 x 5.5 | 50.50 |
| 1″ – 8 | 7/8 | M60 x 5.5 | 54.50 |
| 1″ -14 | 15/16 | M64 x 6 | 58.00 |
| M68 x 6 | 62.00 | ||
American Standard and ISO Metric Thread Sizes and Tap Drills Chart
The complete chart of American Standard and ISO Metric thread sizes with corresponding tap drill sizes for accurate threading and machining. Easily find tap drill sizes in both inches and millimeters for various thread types.