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  • 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.
  • 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

Manufacturer

N/A Industrial Fasteners Institute

Specifications

Product

N/A Square and Hex Bolts and Screws

Unit of Measure

N/A English

Nominal Size or Basic Product Diameter

N/A 1-1/4 in

Nominal Size or Basic Product Diameter (Decimal)

N/A 1.2500 in

Max. Full-Size Body Diameter (E)

N/A 1.277 in

Min. Full-Size Body Diameter (E)

N/A 1.223 in

Basic Width Across Flats (F)

N/A 2 in

Max. Width Across Flats (F)

N/A 2.000 in

Min. Width Across Flats (F)

N/A 1.938 in

Max. Width Across Corners (G)

N/A 2.309 in

Min. Width Across Corners (G)

N/A 2.209 in

Basic Head Height (H)

N/A 27/32 in

Max. Head Height (H)

N/A 0.876 in

Min. Head Height (H)

N/A 0.749 in

Max. Radius of Fillet (R)

N/A 0.09 in

Min. Radius of Fillet (R)

N/A 0.030 in

Codes and Standards

Codes and Standards

N/A ASME B18.2.1 1996

Thread Length for Bolt Lengths

Nom. LT for Bolt Length (6 in. and Shorter)

N/A 2.750 in

Nom. LT for Bolt Length (Over 6 in.)

N/A 3.000 in