- Top of Head. Top of head shall be full form and chamfered, with the diameter of chamfer circle being equal to the maximum width across flats within a tolerance of minus 15 percent.
- Wrenching Height, J. Wrenching height is a distance measured from the bearing surface up the side of the head at the corners. The width across corners shall be within specified limits for the full wrenching height.
- Bearing Surface. Bearing surface shall be flat and washer
Unit of Measure
Specifications
Product |
N/A Square and Hex Bolts and Screws |
Unit of Measure |
N/A English |
Nominal Size or Basic Product Diameter |
N/A 5/16 in |
Nominal Size or Basic Product Diameter (Decimal) |
N/A 0.3125 in |
Max. Body Diameter (E) |
N/A 0.3125 in |
Min. Body Diameter (E) |
N/A 0.3065 in |
Basic Width Across Flats (F) |
N/A 1/2 in |
Max. Width Across Flats (F) |
N/A 0.500 in |
Min. Width Across Flats (F) |
N/A 0.489 in |
Max. Width Across Corners (G) |
N/A 0.577 in |
Min. Width Across Corners (G) |
N/A 0.557 in |
Basic Head Height (H) |
N/A 13/64 in |
Max. Head Height (H) |
N/A 0.211 in |
Min. Head Height (H) |
N/A 0.195 in |
Min. Wrenching Height (J) |
N/A 0.140 in |
Max. Transition Thread Length (Y) |
N/A 0.278 in |
Max. Circular Runout of Bearing Surface FIM |
N/A 0.011 in |