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MS9558-21
Military Standard Machine Bolt
Description
Fastener Length: 1-1/2", Thread: 5/16-24, Thread Length: 7/8", MS9558 series bolt
Specifications
| Extended Washer Diameter | 1/2 |
|---|---|
| Extended Washer Thickness | 0.07 |
| Fastener Length | 1 1/2 |
| Features Provided | Finished head |
| Grip Length | Between 0.628 inches and 0.688 inches |
| Hardness Rating | 24.0 rockwell c and 35.0 rockwell c |
| Head Height | 0.348 |
| Head Style | Double hexagon with hole |
| Length | 1 1/2 |
| Material | Iron |
| Material Specification | Ams 5731 assn standard single material response |
| Min. Tensile Strength (psi) | 130000 pounds per square inch |
| Minimum Yield Strength | 85000 pounds per square inch |
| Surface Finish | 32.0 microinches grip, 32.0 microinches surface of head, 32.0 microinches threads |
| Thread Class | 3a |
| Thread Diameter | 0.312 |
| Thread Direction | Right-hand |
| Thread Length | 7/8 |
| Thread Qty | 24 |
| Thread Qty Per Inch (tpi) | 24 |
| Thread Series | UNJF |
| Thread Series Designator | Unjf (fine thread with external controlled root radius) |
| Thread Size | 5/16 |
| Width Between Flats | 0.375 |
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 MS9558-21. Try the cross-reference lookup to search by a different part number.
Catalog data updated 2026-07-05. Report a data error