- Thread Class
- 3A
- Thread Direction
- Right-hand
- Thread Length
- 0.563 inches minimum and 0.594 inches maximum
- Fastener Length
- 0.625 inches minimum and 0.687 inches maximum
- Head Style
- Crowned hexagon
- Head Height
- 0.141 inches nominal
- Width Between Flats
- 0.428 inches minimum and 0.460 inches maximum
- Hole Diameter
- 0.062 inches nominal
- Nominal Thread Diameter
- 0.250 inches
- Grip Length
- 0.031 inches minimum and 0.062 inches maximum
- Hole Quantity
- 1
- Hole Type
- Drilled
- Features Provided
- Finished head
- Thread Quantity per Inch
- 28
- Minimum Tensile Strength
- 125000 pounds per square inch
- Hardness Rating
- 26.0 rockwell C minimum overall and 32.0 rockwell C maximum overall
- Hole Configuration Style
- Hexagon flats
- Material
- Steel comp 4140 overall or steel comp 8740 overall or steel comp 8630 overall or steel comp 8735 overall or steel comp 4130 overall or steel comp 4037 overall
- Surface Treatment
- Cadmium overall and chromate overall
- Surface Treatment Document and Classification
- QQ-P-416 fed spec single treatment response overall
- Thread Series Designator
- UNF
- 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.