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AN4-37A
Aeronautical Standard Machine Bolt
Description
Airframe Bolt
Specifications
| Country of Origin | USA |
|---|---|
| Drilling | Undrilled Head |
| Fastener Length | 3.906 |
| Features Provided | Finished head |
| Grip | 3 7/16 in |
| Grip Length | 3 7/16, 3.438 |
| Hardness Rating | 26.0 rockwell c and 32.0 rockwell c |
| Head Height | Between 0.140 inches and 0.172 inches |
| Head Style | Hexagon Head |
| Head Type | Hexagon |
| Industry Standards/Certification | AN4 |
| Length | 3 29/32 in |
| Material | Steel |
| Min. Tensile Strength (psi) | 125000 pounds per square inch |
| NIIN | 00-151-1401 |
| NSN | 5306-00-151-1401 |
| Nominal Length | 3 29/32 |
| Surface Treatment | Cadmium and chromate |
| Thread Class | 3a |
| Thread Diameter | 0.250 |
| Thread Direction | Right-hand |
| Thread Length | 0.468 |
| Thread Qty | 28 |
| Thread Qty Per Inch (tpi) | 28 |
| Thread Series | UNF |
| Thread Series Designator | Unf (fine thread) |
| Thread Size | 1/4-28 |
| Weight | 0.06 lb |
| Width Between Flats | Between 0.428 inches and 0.440 inches |
Cross-reference
No interchangeable or dimensionally similar parts are on record for AN4-37A. Try the cross-reference lookup to search by a different part number.
Catalog data updated 2026-07-05. Report a data error