- Thread Class
- 3A
- Thread Direction
- Right-hand
- Thread Length
- 0.316 in nominal
- Fastener Length
- 0.628 in nominal
- Head Style
- Flat countersunk
- Head Diameter
- 0.449 in nominal
- Grip Diameter
- 0.248 in min / 0.249 in max
- Internal Drive
- Offset cruciform (torque set)
- Nominal Thread Diameter
- 0.250 in (1/4-28 UNJF)
- Grip Length
- 0.312 in nominal
- Threads per Inch
- 28
- Min Tensile Strength
- 160,000 psi
- Countersink Angle
- 99.0 deg min / 101.0 deg max
- Material
- Iron alloy 660 per AMS 5737
- Surface Treatment
- Cadmium per QQ-P-416, Type II, Class 2
- Thread Series
- UNJF
Catalogue data is compiled from public DLA/FLIS sources and is provided for
identification. Availability, condition and certification are confirmed on
quotation. OmniSynk Distribution Services is a stocking distributor.