- Thread Class
- 3A
- Thread Direction
- Right-hand
- Thread Length
- 0.378 inches minimum and 0.428 inches maximum
- Fastener Length
- 1.388 inches minimum and 1.418 inches maximum
- Head Style
- Flat countersunk
- Head Diameter
- 0.464 inches minimum and 0.506 inches maximum
- Shoulder Diameter
- 0.2797 inches minimum first shoulder and 0.2807 inches maximum first shoulder
- Shoulder Length
- 0.990 inches minimum first shoulder and 1.010 inches maximum first shoulder
- Internal Drive Style
- Offset cruciform (torque set)
- 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 overall and 40.0 rockwell C maximum overall
- Countersink Angle
- 99.0 degrees minimum and 101.0 degrees maximum
- Shoulder Shape
- Round first shoulder
- Material
- Steel comp 4140 overall or steel comp E4340 overall or steel comp 8740 overall
- Material Document and Classification
- MIL-S-5626 mil spec 1ST material response overall or MIL-S-5000 mil spec 2ND material response overall or MIL-S-6049 mil spec 3RD material response overall
- Surface Treatment
- Cadmium overall and chromate overall
- Surface Treatment Document and Classification
- QQ-P-416, ty 2 cl 2 fed spec single treatment response overall
- Thread Series Designator
- 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.