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MS21280-10
Military Standard Machine Bolt
Description
Fastener Length: 3/4", Thread: 1/4-28, Thread Length: 11/16"
Specifications
| Extended Washer Diameter | 0.438 |
|---|---|
| Extended Washer Thickness | 0.060 inches minimum and 0.070 inches maximum |
| Fastener Length | 0.750 |
| Features Provided | Finished head |
| Hardness Rating | 248.0 brinell standard minimum and 341.0 brinell standard maximum |
| Head Height | 0.330 |
| Head Style | Double hexagon w/hole |
| Length | 3/4 |
| Material | Iron |
| Material Specification | Ams 5735 assn std 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 threads, 63.0 microinches bearing surface of head, 63.0 microinches grip |
| Thread Class | 3a |
| Thread Diameter | 0.250 |
| Thread Direction | Right-hand |
| Thread Length | 0.679 inches minimum and 0.750 inches maximum |
| Thread Qty | 28 |
| Thread Qty Per Inch (tpi) | 28 |
| Thread Series Designator | UNJF |
| Thread Size | 1/4 |
| Width Between Flats | 0.304 inches minimum and 0.313 inches maximum |
Other sizes
Parts that share this base number, ordered by size. Always verify the full specification before substituting.
Cross-reference
Similar parts
Parts with matching key dimensions — often from a different standards family. Candidates for comparison only; verify the full specification before substituting.
- MS21280-11 MS 1/4-28 · 3/4 in · Double hexagon w/hole · Iron
- MS9034-10 MS 1/4-28 · 3/4 in · Double hexagon w/hole · Iron
- MS9034-11 MS 1/4-28 · 3/4 in · Double hexagon w/hole · Iron
- MS9147-10 MS 1/4-28 · 3/4 in · Double hexagon w/hole · Steel
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Catalog data updated 2026-07-05. Report a data error