- 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%.
- 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 the specified limits for minimum wrenching height.
- Bearing Surface. Bearing surface shall be flat and washer faced. Diameter of washer face shall be equal to the maximum width across flats within a tolerance of minus 10 percent.
Thickness of the washer face shall be not less than 0.015 in. nor greater than 0.025 in. for screw sizes 3/4 in. and smaller, and not less than 0.015 in. nor greater than 0.035 in. for sizes larger than 3/4 in. Measurement of washer face diameter shall be taken at a height of 0.004 in. above the bearing surface.
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 7/8 in |
Nominal Size or Basic Product Diameter (Decimal) |
N/A 0.8750 in |
Max. Body Diameter (E) |
N/A 0.8750 in |
Min. Body Diameter (E) |
N/A 0.852 in |
Basic Width Across Flats (F) |
N/A 1-7/16 in |
Max. Width Across Flats (F) |
N/A 1.438 in |
Min. Width Across Flats (F) |
N/A 1.394 in |
Max. Width Across Corners (G) |
N/A 1.660 in |
Min. Width Across Corners (G) |
N/A 1.589 in |
Basic Head Height (H) |
N/A 35/64 in |
Max. Head Height (H) |
N/A 0.563 in |
Min. Head Height (H) |
N/A 0.531 in |
Min. Wrenching Height (J) |
N/A 0.378 in |
Max. Transition Thread Length (Y) |
N/A 0.556 in |
Max. Circular Runout of Bearing Surface FIM |
N/A 0.025 in |