- Thread Class
- 3A
- Thread Direction
- Right-hand
- Thread Length
- 2.688 inches minimum and 2.721 inches maximum
- Fastener Length
- 2.750 inches minimum and 2.752 inches maximum
- Head Style
- Crowned hexagon
- Head Height
- 0.162 inches minimum and 0.182 inches maximum
- Width Between Flats
- 0.490 inches minimum and 0.502 inches maximum
- Nominal Thread Diameter
- 0.312 inches
- Grip Length
- 0.031 inches minimum and 0.062 inches maximum
- Features Provided
- Finished head
- Thread Quantity per Inch
- 24
- Minimum Tensile Strength
- 125000 pounds per square inch
- Hardness Rating
- 26.0 rockwell C minimum overall and 32.0 rockwell C maximum overall
- Material
- Steel comp 4037 overall or steel comp 4130 overall or steel comp 8630 overall or steel comp 8735 overall or steel comp 8740 overall or steel comp 4140 overall
- Surface Treatment
- Cadmium overall and chromate overall
- Surface Treatment Document and Classification
- QQ-P-416 type 2 class 2 fed spec single treatment response overall
- Thread Series Designator
- UNJF
- Specification/Standard Data
- 80205-NAS428 professional/industrial association standard
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.