Preferred Sizes
This page provides lists of preferred sizes in terms of inches and millimeters. This is useful for selecting stock thicknesses, bolt lengths, and other mechanical dimensions. These lists are adapted from Shigley.
Inches (Fractions)
1⁄64 , 1⁄32 , 1⁄16 , 3⁄32 , 1⁄8 , 5⁄32 , 3⁄16 , 1⁄4 , 5⁄16 , 3⁄8 , 7⁄16 , 1⁄2 , 9⁄16 , 5⁄8 , 11⁄16 , 3⁄4 , 7⁄8 , 1, 11⁄4 , 11⁄2 , 13⁄4 , 2, 21⁄4 , 21⁄2 , 23⁄4 , 3, 31⁄4 , 31⁄2 , 33⁄4 , 4, 41⁄4 , 41⁄2 , 43⁄4 , 5, 51⁄4 , 51⁄2 , 53⁄4 , 6, 61⁄2 , 7, 71⁄2 , 8, 81⁄2 , 9, 91⁄2 , 10, 101⁄2 , 11, 111⁄2 , 12, 121⁄2 , 13, 131⁄2 , 14, 141⁄2 , 15, 151⁄2 , 16, 161⁄2 , 17, 171⁄2 , 18, 181⁄2 , 19, 191⁄2 , 20
Millimeters
0.05, 0.06, 0.08, 0.10, 0.12, 0.16, 0.20, 0.25, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.0, 1.1, 1.2, 1.4, 1.5, 1.6, 1.8, 2.0, 2.2, 2.5, 2.8, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 8.0, 9.0, 10, 11, 12, 14, 16, 18, 20, 22, 25, 28, 30, 32, 35, 40, 45, 50, 60, 80, 100, 120, 140, 160, 180, 200, 250, 300
We have a number of structural calculators to choose from. Here are just a few:
