- Thread Class
- 3A
- Thread Direction
- Right-hand
- Thread Length
- 0.813 inches minimum and 0.906 inches maximum
- Fastener Length
- 0.875 inches minimum and 0.937 inches maximum
- Head Style
- Crowned hexagon
- Head Height
- 0.141 inches nominal
- Width Between Flats
- 0.428 inches minimum and 0.440 inches maximum
- Nominal Thread Diameter
- 0.250 inches
- Grip Length
- 0.031 inches minimum and 0.062 inches maximum
- 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
- Special Features
- Slot in thd end 0.061 in. min 0.077 in. max by 0.097 in. min 0.130 in. max deep
- Material
- Steel comp 8740 overall or steel comp 8630 overall or steel comp 8735 overall or steel comp 4130 overall or steel comp 4037 overall or steel comp 4140 overall
- Material Document and Classification
- MIL-S-6049 mil spec 1ST material response overall or MIL-S-6050 mil spec 2ND material response overall or MIL-S-6098 mil spec 3RD material response overall or MIL-S-6758 mil spec 4TH material response overall or ams 6300 assn std 5TH material response overall or MIL-S-5626 mil spec 6TH material response overall
- Surface Treatment
- Cadmium overall and chromate overall
- Surface Treatment Document and Classification
- QQ-P-416, type 2, cl 3 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.