bolts › machine bolts
MS9557-05
Military Standard Machine Bolt
Description
Fastener Length: 7/16", Thread: 1/4-28, Thread Length: 23/64", hexagon with hole head, fine thread, stainless steel, MS9557 series bolt
Specifications
| Extended Washer Diameter | Between 0.428 inches and 0.438 inches |
|---|---|
| Extended Washer Thickness | 0.060 |
| Fastener Length | Between 0.428 inches and 0.448 inches |
| Features Provided | Finished head |
| Grip Length | Between 0.079 inches and 0.099 inches |
| Hardness Rating | 24.0 rockwell c and 35.0 rockwell c |
| Head Height | Between 0.290 inches and 0.310 inches |
| Head Style | Double hexagon w/hole |
| Length | 7/16 |
| Material | Iron |
| Material Specification | Ams5731 assn standard single material response |
| Min. Tensile Strength (psi) | 85000 pounds per square inch |
| Minimum Yield Strength | 130000 pounds per square inch |
| Surface Finish | 32.0 microinches bearing surface of head, 32.0 microinches grip, 32.0 microinches threads |
| Thread Class | 3a |
| Thread Diameter | 0.250 |
| Thread Direction | Right-hand |
| Thread Length | Between 0.329 inches and 0.369 inches |
| Thread Qty | 28 |
| Thread Qty Per Inch (tpi) | 28 |
| Thread Series | UNJF |
| Thread Series Designator | Unjf (fine thread with external controlled root radius) |
| Thread Size | 1/4 |
| Width Between Flats | 0.313 |
Cross-reference
No interchangeable or dimensionally similar parts are on record for MS9557-05. Try the cross-reference lookup to search by a different part number.
Catalog data updated 2026-07-05. Report a data error