- Thread Class
- 3A
- Thread Direction
- Right-hand
- Thread Length
- 0.400 inches minimum and 0.450 inches maximum
- Fastener Length
- 0.660 inches minimum and 0.690 inches maximum
- Head Style
- Flat countersunk
- Head Diameter
- 0.389 inches minimum and 0.394 inches maximum
- Internal Drive Style
- Cross recess type ii
- Nominal Thread Diameter
- 0.250 inches
- Thread Quantity per Inch
- 28
- Minimum Tensile Strength
- 160000 pounds per square inch
- Hardness Rating
- 36.0 rockwell C minimum and 40.0 rockwell C maximum
- Countersink Angle
- 99.0 degrees minimum and 101.0 degrees maximum
- Screw Material
- Steel comp 4130
- Screw Material Document and Classification
- MIL-S-6758, cond D4 mil spec single material response
- Screw Surface Treatment
- Cadmium and chromate
- Screw Surface Treatment Document and Classification
- QQ-P-416, type 2CLASS 3 fed spec single treatment response
- Thread Series Designator
- UNF
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.