bolts › close tolerance bolts
AN174C21A
Aeronautical Standard Close Tolerance Bolt
Description
Fastener Length: 2-3/16", Thread: 1/4-28, Thread Length: 1/2", hexagon head, fine thread, AN174 series bolt
Specifications
| Fastener Length | Between 2.141 inches and 2.188 inches |
|---|---|
| Grip Diameter | Between 0.2487 inches and 0.2492 inches |
| Grip Length | Between 1.672 inches and 1.703 inches |
| 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 |
| Material | Steel |
| Material Specification | Mil-s-18732 military specification single material response |
| Min. Tensile Strength (psi) | 125000 pounds per square inch |
| Surface Treatment | Passivate |
| Thread Class | 3a |
| Thread Diameter | 0.250 |
| Thread Direction | Right-hand |
| Thread Length | Between 0.438 inches and 0.515 inches |
| Thread Qty | 28 |
| Thread Qty Per Inch (tpi) | 28 |
| Thread Series | UNF |
| Thread Series Designator | Unf (fine thread) |
| Thread Size | 1/4 |
| Width Between Flats | Between 0.428 inches and 0.440 inches |
Other sizes
Parts that share this base number, ordered by size. Always verify the full specification before substituting.
Cross-reference
No interchangeable or dimensionally similar parts are on record for AN174C21A. Try the cross-reference lookup to search by a different part number.
Catalog data updated 2026-07-05. Report a data error