• Hexagon machine screw nuts shall have tops flat with chamfered corners. Diameter of top circle shall be equal to the maximum width across flats within a tolerance of minus 15 percent. The bearing surface shall be perpendicular to the axis of the threaded hole pitch cylinder within a tolerance of 4 deg.
  • Bottoms of hexagon machine screw nuts are normally flat, but for special purposes may be chamfered, if so specified by purchaser.
  • Where specifying nominal size in decimals, zeros preceding decimal and in the fourth decimal place shall be omitted.
Unit of Measure

Manufacturer

Manufacturer

N/A Industrial Fasteners Institute

Specifications

Product

N/A Machine Screw Nuts

Unit of Measure

N/A English

Nominal Size or Basic Thread Dia.

N/A No. 5

Nominal Size or Basic Thread Dia. (Decimal)

N/A 0.1250 in

Basic Width Across Flats (F)

N/A 5/16 in

Max. Width Across Flats (F)

N/A 0.312 in

Min. Width Across Flats (F)

N/A 0.302 in

Max. Width Across Corners (G1)

N/A 0.361 in

Min. Width Across Corners (G1)

N/A 0.344 in

Max. Thickness (H)

N/A 0.114 in

Min. Thickness (H)

N/A 0.102 in

Codes and Standards

Codes and Standards

N/A ANSI/ASME B18.6.3 1998
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