- Thread Series
- UNF
- Thread Diameter
- 0.250 inches (1/4-28)
- Threads Per Inch
- 28
- Thread Class
- 3A
- Thread Direction
- Right-hand
- Thread Length
- 0.316 inches minimum
- Fastener Length
- 0.863-0.893 inches (57/64 in. nominal)
- Grip Diameter
- 0.2485-0.2495 inches (Close Tolerance)
- Material
- Alloy Steel (4140, E4340, 6150, 8735, or 8740)
- Surface Treatment
- Cadmium and Chromate (QQ-P-416, Type 2, Class 3)
- Hardness
- 36.0-40.0 Rockwell C
- Tensile Strength (Min)
- 160,000 PSI
- Head Style
- Flat Countersunk 100 degrees
- Head Diameter
- 0.449-0.507 inches
- Drive Type
- Cross Recess Type 1
- Shank Feature
- Drilled (D suffix) — first hole 0.076 in. nominal
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.