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MS9218-20
Military Standard Machine Bolt
Description
Fastener Length: 1-3/8", Thread: 1/4-28, Thread Length: 13/16
Specifications
| Extended Washer Diameter | Between 0.428 inches and 0.448 inches |
|---|---|
| Extended Washer Thickness | Between 0.060 inches and 0.070 inches |
| Fastener Length | Between 1.365 inches and 1.385 inches |
| Features Provided | Finished head |
| Grip Length | Between 0.565 inches and 0.625 inches |
| Hardness Rating | 42.0 rockwell c and 46.0 rockwell c |
| Head Height | Between 0.320 inches and 0.340 inches |
| Head Style | Double hexagon w/hole |
| Material | CRES |
| Material Specification | Ams6304 assn standard single material response |
| Surface Finish | 32.0 microinches bearing surface of head, 32.0 microinches grip, 32.0 microinches threads |
| Surface Treatment | Nickel and cadmium |
| Surface Treatment Specification | Ams2416 assn standard single treatment response |
| Thread Class | 3a |
| Thread Diameter | 0.250 |
| Thread Direction | Right-hand |
| Thread Length | Between 0.740 inches and 0.820 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 | Between 0.305 inches and 0.313 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 MS9218-20. Try the cross-reference lookup to search by a different part number.
Catalog data updated 2026-07-05. Report a data error