Imperial to Metric Comparison & Conversion Charts
Fastener Diameter & Thread
Diameter | Diameter (Inches) | Threads Per Inch (U.N.C.) | Pitch (millimeters) |
| #0 | 0.060" | 80 | - |
| M1.6 | 0.063" | 74 (Approx) | 0.35 mm |
| #1 | 0.073" | 64 | - |
| M2 | 0.079" | 64 (Approx) | 0.4 mm |
| #2 | 0.096" | 56 | - |
| M2.5 | 0.098" | 56 (Approx) | 0.45 mm |
| #3 | 0.099" | 48 | - |
| #4 | 0.112" | 40 | - |
| M3 | 0.118" | 51 (Approx) | 0.5 mm |
| #5 | 0.125" | 40 | - |
| #6 | 0.138" | 32 | - |
| M4 | 0.157" | 36 (Approx) | 0.7 mm |
| #8 | 0.164" | 32 | - |
| #10 | 0.190" | 24 | - |
| M5 | 0.196" | 32 (Approx) | 0.8 mm |
| M6 | 0.236" | 25 (Approx) | 1 mm |
| 1/4" | 0.250" | 20 | - |
| 5/16" | 0.312" | 18 | - |
| M8 | 0.315" | 20 (Approx) | 1.25 mm |
| 3/8" | 0.375" | 16 | - |
| M10 | 0.393" | 17 (Approx) | 1.5 mm |
| 7/16" | 0.437" | 14 | - |
| M12 | 0.472" | 14.5 (Approx) | 1.75 mm |
| 1/2" | 0.5" | 13 | - |
| M14 | 0.551" | 12.5 (Approx) | 2 mm |
| 5/8" | 0.625" | 11 | - |
| M16 | 0.63" | 10 (Approx) | 2 mm |
| 3/4" | 0.75" | 10 | - |
| M20 | 0.787" | 10 (Approx) | 2.5 mm |
| 7/8" | 0.875" | 9 | - |
| M24 | 0.945" | 8.5 (Approx) | 3 mm |
| 1" | 1" | 8 | - |
| M27 | 1.063" | 8.5 (Approx) | 3 mm |
Last Updated: Dec 12, 2016
Update History:
Dec 12, 2016 by jsjohnson from Calgary Fasteners
May 16, 2016 by jsjohnson from Calgary Fasteners
May 16, 2016 by jsjohnson from Calgary Fasteners
Jan 7, 2016 by jsjohnson from Calgary Fasteners
