bolts › close tolerance bolts
AN174-6A
Aeronautical Standard Close Tolerance Bolt
Description
Close Tolerance Bolt
Specifications
| Country of Origin | USA |
|---|---|
| Drilling | Undrilled Head |
| Fastener Length | 0.781 |
| Grip | 5/16 in |
| Grip Diameter | Between 0.2487 inches and 0.2492 inches |
| Grip Length | 0.312 |
| Hardness Rating | 26 rockwell c and 32 rockwell c |
| Head Height | Between 0.14 inches and 0.172 inches |
| Head Style | Hexagon Head |
| Head Type | Hexagon |
| Industry Standards/Certification | AN174 |
| Length | 25/32 in, 3/4 |
| Material | Steel |
| Min. Tensile Strength (psi) | 125000 pounds per square inch |
| NIIN | 00-206-4910 |
| NSN | 5306-00-206-4910 |
| Surface Finish | 63 microinches bearing surface of head, 63 microinches grip |
| Surface Treatment | Cadmium and chromate |
| Thread Class | 3a |
| Thread Diameter | 0.25 |
| Thread Direction | Right-hand |
| Thread Length | 0.469 |
| Thread Qty | 28 |
| Thread Qty Per Inch (tpi) | 28 |
| Thread Series | UNF |
| Thread Series Designator | Unf (fine thread) |
| Thread Size | 0.2500-28, 1/4 |
| Weight | 0.02 lb |
| Width Between Flats | Between 0.428 inches and 0.44 inches |
Cross-reference
No interchangeable or dimensionally similar parts are on record for AN174-6A. Try the cross-reference lookup to search by a different part number.
Catalog data updated 2026-07-05. Report a data error