Formula For Unified Number Screw Sizes To Find The Diameter
Wonder how to find the diameter for unified screw sizes under 1/4” with #12, #10, #8, #6 etc. Use the following equation to find the nominal diameter of screw.
Diameter = Screw Size # × 0.013" + 0.060" for example to find the #1 screw diameter 1 x 0.013 + 0.060 = 0.073”.
These numbering system designed in such a way that tensile strength of the screw approximately doubles with each screw number size. That is #2 screw will have approximately double the strength of #1 screw.