Applicable to screw types as indicated by code symbols.
  • Type AB thread forming.
  • Types B and BP thread forming and Types BF and BT thread cutting.
  • Type C thread forming and Types D, F, G, and T thread cutting.
Unit of Measure

Manufacturer

Manufacturer

Industrial Fasteners Institute

Specifications

Product

Tapping Screws

Unit of Measure

English

Nominal Size or Basic Screw Dia.

No. 8

Nominal Size or Basic Screw Dia. (Decimal)

0.1640 in
Applicable to Screw Types1 1
3
4

Length for Types AB and A (L)

7/16 in

Length for Other Types (LT)

7/16 in

Max. Head Dia. (A)

0.312 in

Min. Head Dia. (A)

0.285 in

Max. Head Height (H)

0.070 in

Min. Head Height (H)

0.058 in

Max. Slot Width (J)

0.054 in

Min. Slot Width (J)

0.045 in

Max. Slot Depth (T)

0.032 in

Min. Slot Depth (T)

0.021 in

Max. Protrusion Above Gaging Dia. (F)

0.039 in

Min. Protrusion Above Gaging Dia. (F)

0.023 in

Gaging Dia. (G)

0.267 in

Codes and Standards

Codes and Standards

Abstract of ASME B18.6.4 1998
  • 1 1 = Circle, 3 = Triangle, 4 = Square
Use trailing wildcard (*) for broader results.