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MS16997-9L
Military Standard Screw
Description
Fastener Length: 1/4", Thread: 4-40, Head Width: 3/32", Thread Length: 1/4"
Specifications
| Fastener Length | 0.219 inches minimum and 0.250 inches maximum |
|---|---|
| Hardness Rating | 38.0 rockwell c minimum and 45.0 rockwell c maximum |
| 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 | 1/4 |
| Locking Feature | Patch threads |
| Material | Steel |
| Min. Tensile Strength (psi) | 180000 pounds per square inch |
| Minimum Yield Strength | 155000 pounds per square inch |
| Nondefinitive Specification/Std Data | 6 type |
| Surface Treatment | Cadmium and chromate |
| Surface Treatment Specification | Qq-p-416,type 2,class 3 fed spec single treatment response |
| Thread Class | 3a |
| Thread Diameter | 0.112 |
| Thread Direction | Right-hand |
| Thread Length | 0.169 inches minimum and 0.250 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 |
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.
- NAS1352-04-4 NAS #4-40 · 1/4 in · Flat chamfer · Steel
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- NAS1352C04LE4 NAS #4-40 · 1/4 in · Flat chamfer · CRES
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Catalog data updated 2026-07-05. Report a data error