This type of recess has a large center opening, wide straight wings, and blunt bottom, with all edges relieved or rounded.
Applicable to screw types as indicated by code symbols.
Applicable to screw types as indicated by code symbols.
- 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
Specifications
Product |
N/A Tapping Screws |
Unit of Measure |
N/A English |
Type |
N/A Type IA Long Screws with Shoulder |
Nominal Size or Basic Screw Dia. |
N/A 3/8 in |
Nominal Size or Basic Screw Dia. (Decimal) |
N/A 0.3750 in |
Head Size |
N/A 5/16 in |
Applicable to Screw Types1 |
N/A
3 4 |
Ref. Recess Dia. (M) |
N/A 0.384 in |
Ref. Recess Depth ((T) |
N/A 0.232 in |
Ref. Recess Width (N) |
N/A 0.086 in |
Driver Size |
N/A 4 |
Max. Recess Penetration Gaging Depth |
N/A 0.215 in |
Min. Recess Penetration Gaging Depth |
N/A 0.197 in |
Max. Protrusion Above Gaging Dia. (F) |
N/A 0.155 in |
Min. Protrusion Above Gaging Dia. (F) |
N/A 0.117 in |
Gaging Dia. (G) |
N/A 0.539 in |
- 1 1 = Circle, 2 = Diamond, 3 = Triangle, 4 = Square