• Where specifying nominal size in decimals, zeros preceding decimal and in the fourth decimal place shall be omitted.
  • Head to rib tolerance on the No. 10 through 1/2" sizes for nominal lengths 7/8 in. and shorter shall be +0.031 and -0.000.
  • The minimum radius is one half of the value shown.
Unit of Measure

Manufacturer

Manufacturer

N/A Industrial Fasteners Institute

Specifications

Product

N/A Round Head Bolts

Unit of Measure

N/A English

Nominal Size or Basic Bolt Dia.

N/A 5/16 in

Nominal Size or Basic Bolt Dia. (Decimal)

N/A 0.3125 in

Max. Body Dia. (E)

N/A 0.324 in

Min. Body Dia. (E)

N/A 0.298 in

Max. Head Dia. (A)

N/A 0.719 in

Min. Head Dia. (A)

N/A 0.688 in

Max. Head Height (H)

N/A 0.176 in

Min. Head Height (H)

N/A 0.156 in
Head to Ribs for Lengths of 7/8 and Shorter (M)1 N/A 0.031 in
Head to Ribs for Lengths of 1 in. and Longer (M)2 N/A 0.063 in

Approx. Number of Ribs (N)

N/A 12

Min. Dia. Over Ribs (O)

N/A 0.340 in
Depth Over Ribs for Lengths of 7/8 and Shorter (P)3 N/A 0.250 in
Depth Over Ribs for Lengths of 1 in. and Longer (P)4 N/A 0.407 in
Depth Over Ribs for Lengths of 1-1/4 and Longer (P)5 N/A 0.594 in

Max. Fillet Radius (R)

N/A 0.031 in

Codes and Standards

Codes and Standards

N/A ASME B18.5 1990 (R1998)
  • 1 Tolerance ±0.031
  • 2 Tolerance ±0.031
  • 3 Tolerance ±0.031
  • 4 Tolerance ±0.031
  • 5 Tolerance ±0.031
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