- Thread Class
- 3A
- Thread Direction
- Right-hand
- Thread Length
- 1.250 inches maximum
- Fastener Length
- 1.190 inches minimum and 1.250 inches maximum
- Head Style
- Flat chamfer
- Head Diameter
- 0.642 inches minimum and 0.656 inches maximum
- Head Height
- 0.430 inches minimum and 0.437 inches maximum
- Internal Drive Style
- Hexagon
- Nominal Thread Diameter
- 0.438 inches
- Width Across Flats
- 0.375 inches minimum and 0.379 inches maximum
- Thread Quantity per Inch
- 20
- Minimum Tensile Strength
- 160000 pounds per square inch
- Hardness Rating
- 33.0 rockwell C minimum and 42.0 rockwell C maximum overall
- Part Name Assigned BY Controlling Agency
- Navy special project
- Material
- Iron alloy 660 overall
- Material Document and Classification
- AMS5731 assn std single material response and AMS5737 assn std single material response overall
- Surface Treatment
- Passivate overall
- Surface Treatment Document and Classification
- QQ-P-35 fed spec single treatment response overall
- Thread Series Designator
- UNRF
- Specification/Standard Data
- 80205-NAS1531 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.