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MS51959-14B
Military Standard Machine Screw
Description
Fastener Length: 5/16", Thread: 4-40, Thread Length: 15/64"
Specifications
| Countersink Angle | 80.0 degrees minimum and 82.0 degrees maximum |
|---|---|
| Departure From Cited Designator | As modified by finish |
| Fastener Length | 0.281 inches minimum and 0.312 inches maximum |
| Head Diameter | 0.195 inches minimum and 0.225 inches maximum |
| Head Style | Flat countersunk |
| Internal Drive Style | Cross recess type 1 |
| Length | 5/16 |
| Material | CRES |
| Min. Tensile Strength (psi) | 80000 pounds per square inch |
| Nondefinitive Specification/Std Data | 3 type and 2c style |
| Screw Material | Steel corrosion resisting or steel |
| Screw Material Specification | Qq-s-763,300 series fed spec 1st material response or 66,300 series fed std 1st material response or comp 16-18 or 18-8 assn std 2nd material response |
| Screw Surface Treatment | Oxide |
| Screw Surface Treatment Specification | Mil-c-13924,cl 4 mil spec single treatment response |
| Thread Class | 2a |
| Thread Diameter | 0.112 |
| Thread Direction | Right-hand |
| Thread Length | 0.164 inches minimum and 0.245 inches maximum |
| Thread Qty | 40 |
| Thread Qty Per Inch (tpi) | 40 |
| Thread Series Designator | UNC |
| Thread Size | 4 |
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.
- MS18211-19C MS #4-40 · 5/16 in · Flat countersunk
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Catalog data updated 2026-07-05. Report a data error