Item # HCS03125XXX, Hex Cap Screw, 5/16" Nominal Dia. On Sales Systems Ltd.

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

Manufacturer | Specifications | Codes and Standards | Thread Length for Screw Lengths

N/A Industrial Fasteners Institute

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

N/A ASME B18.2.1 1996

Nom. L_T for Screw Length (6 in. and Shorter)	N/A 0.875 in
Nom. L_T for Screw Length (Over 6 in.)	N/A 1.125 in

Manufacturer