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MS51959-4B
Military Standard Machine Screw
Description
Fastener Length: 5/16", Thread: 2-56, Thread Length: 1/4", black oxide
Specifications
| Countersink Angle | Between 80.0 degrees and 82.0 degrees |
|---|---|
| Departure From Cited Designator | As modified by finish |
| Fastener Length | Between 0.281 inches and 0.312 inches |
| Head Diameter | Between 0.147 inches and 0.172 inches |
| 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 | Stainless steel or steel |
| Screw Material Specification | 300 series federal standard 1st material response or comp 16-18 or 18-8 assn standard 2nd material response 300 series federal specification 1st material response or 66 qq-s-763 |
| Screw Surface Treatment | Oxide |
| Screw Surface Treatment Specification | Class 4 military specification single treatment response mil-c-13924 |
| Thread Class | 2a |
| Thread Diameter | 0.086 |
| Thread Direction | Right-hand |
| Thread Length | Between 0.194 inches and 0.261 inches |
| Thread Qty | 56 |
| Thread Qty Per Inch (tpi) | 56 |
| Thread Series | UNC |
| Thread Series Designator | Unc (coarse thread) |
| Thread Size | 2 |
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.
- MS18211-4C MS #2-56 · 5/16 in · Flat countersunk
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Catalog data updated 2026-07-05. Report a data error