Wood Screw / Self-Tapping Screw Diameters and Sizing Imperial To Metric Conversion
Table of wood screw sizes comparing imperial screw size to metric sizing in mm. When choosing wood screws and self-tapping screws some people think in old-school imperial gauge number, some in imperial fractional sizes and some people prefer metric. What ever your preferred screw size lingo the conversion table below should help you select the size of stainless steel wood screw or self-tapping screw that you need. The Gauge # column has clickable links to some of our available stainless steel screws in the nearest sizing.
| Gauge | Decimal Imperial | Nearest Fractional Measurement | Metric |
| #0 | 0.060" | 1/16" | 1.52mm |
| #1 | 0.073" | 5/64" | 1.85mm |
| #2 | 0.086" | 3/32" | 2.18mm |
| #3 | 0.099" | 7/64" | 2.51mm |
| #4 | 0.112" | 7/64" | 2.84mm |
| #5 | 0.125" | 1/8" | 3.18mm |
| #6 | 0.138" | 9/64" | 3.51mm |
| #7 | 0.151" | 5/32" | 3.84mm |
| #8 | 0.164" | 5/32" | 4.17mm |
| #9 | 0.177" | 11/64" | 4.5mm |
| #10 | 0.190" | 3/16" | 4.83mm |
| #11 | 0.203" | 13/64" | 5.16mm |
| #12 | 0.216" | 7/32" | 5.49mm |
| #14 | 0.242" | 1/4" | 6.15mm |
| #16 | 0.268" | 17/64" | 6.81mm |
| #18 | 0.294" | 19/64" | 7.47mm |
| #20 | 0.32" | 5/16" | 8.13mm |
