Nominal Size or Basic Screw Diameter | Head Diameter | Head Height | Head Chamfer | Hex Socket Size | Key Engagement | Wall Thickness | Edge of Head Chamfer | Length | ||
Max | Min | Max | Min | Max | Nom | Min | Min | Max | Under Head | |
1/4" (0.2500) | 0.375 | 0.365 | 0.250 | 0.244 | 0.025 | 3/16 (0.188) | 0.120 | 0.095 | 0.010 | 7/8 |
SEE NOTES 1 | 3 | 4 | 20 | 6 | 9, 10, 11 |
Reprinted from ASME/ANSI B18.3 by permission of The American Society of Mechanical Engineers. All rights reserved. For a full copy of the standards, contact the ASME at http://www.asme.org/codes/.