Item # SB03125XXX, Square Bolt, 5/16" Nominal Dia. On Sales Systems Ltd.

Surface Condition. Bolts need not be finished on any surface except threads.
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.
Head Taper. Maximum width across flats and across corners shall not be exceeded. No transverse section through the head between 25 percent and 75 percent of actual head height, as measured from the bearing surface, shall be less than the minimum width across flats and across corners.
Bearing Surface. A die seam across the bearing surface is permissible. Bearing surface shall be perpendicular to the axis of the body within a tolerance of 3 deg for 1 in. size and smaller, and 2 deg for sizes larger than 1 in. Angularity measurement shall be taken at a location to avoid interference from a die seam. Special bearing surface finishes may be provided as agreed between purchaser and manufacturer.
True Position of Head. The axis of the head shall be located at true position with respect to the axis of the body (determined over a distance under the head equal to one diameter) within a tolerance zone having a diameter equivalent to 6 percent of the maximum width across flats, regardless of feature size.

Unit of Measure

Manufacturer | Specifications | Codes and Standards | Thread Length for Bolt 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. Full-Size Body Diameter (E)	N/A 0.324 in
Min. Full-Size Body Diameter (E)	N/A 0.298 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 0.484 in
Max. Width Across Corners (G)	N/A 0.707 in
Min. Width Across Corners (G)	N/A 0.665 in
Basic Head Height (H)	N/A 13/64 in
Max. Head Height (H)	N/A 0.220 in
Min. Head Height (H)	N/A 0.186 in
Max. Radius of Fillet (R)	N/A 0.03 in
Min. Radius of Fillet (R)	N/A 0.010 in

N/A ASME B18.2.1 1996

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

Manufacturer