screws › socket head cap screws
MS21295-13
Military Standard Socket Head Cap Screw
Description
Fastener Length: 25/64", Thread: 4-40, Head Width: 3/32", Thread Length: 25/64
Specifications
| Departure From Cited Designator | As modified by locking feature |
|---|---|
| Fastener Length | 0.360 inches minimum and 0.390 inches maximum |
| Hardness Rating | 80.0 rockwell b minimum |
| Head Diameter | 0.176 inches minimum and 0.183 inches maximum |
| Head Height | 0.108 inches minimum and 0.112 inches maximum |
| Head Style | Flat chamfer |
| Internal Drive Style | Hexagon |
| Length | 25/64 |
| Locking Feature | Strip threads |
| Material | CRES |
| Material Specification | 66 fed std all material responses |
| Min. Tensile Strength (psi) | 80000 pounds per square inch |
| Minimum Yield Strength | 30000 pounds per square inch |
| Nondefinitive Specification/Std Data | 6 type |
| Surface Treatment | Passivate |
| Surface Treatment Specification | Qq-p-35 fed spec single treatment response |
| Thread Class | 3a |
| Thread Diameter | 0.112 |
| Thread Direction | Right-hand |
| Thread Length | 0.310 inches minimum and 0.390 inches maximum |
| Thread Qty | 40 |
| Thread Qty Per Inch (tpi) | 40 |
| Thread Series Designator | UNC |
| Thread Size | 4 |
| Width Across Flats | 0.094 inches minimum and 0.095 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.
- NAS1352-04-6 NAS #4-40 · 25/64 in · Flat chamfer · Steel
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Catalog data updated 2026-07-05. Report a data error