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NAS517-4-40
Machine Screw
Description
Fastener Length: 2-63/64", Thread: 1/4-28, Thread Length: 1/2"
Specifications
| Countersink Angle | 99.0 degrees minimum and 101.0 degrees maximum |
|---|---|
| Fastener Length | 2.953 inches minimum and 2.998 inches maximum |
| Hardness Rating | 36.0 rockwell c minimum and 40.0 rockwell c maximum |
| Head Diameter | 0.452 inches minimum and 0.510 inches maximum |
| Head Style | Flat countersunk |
| Internal Drive Style | Cross recess type 1 |
| Length | 2 63/64 |
| Material | Steel |
| Min. Tensile Strength (psi) | 160000 pounds per square inch |
| Screw Material | Steel comp 8630 |
| Screw Material Specification | Mil-s-6050 mil spec single material response or an-s-9 mil std single material response |
| Screw Surface Treatment | Cadmium and chromate |
| Screw Surface Treatment Specification | Qq-p-416 ty 2 cl 3 fed spec all treatment responses |
| Thread Class | 3a |
| Thread Diameter | 0.250 |
| Thread Direction | Right-hand |
| Thread Length | 0.367 inches minimum and 0.513 inches maximum |
| Thread Qty | 28 |
| Thread Qty Per Inch (tpi) | 28 |
| Thread Series Designator | UNF |
| Thread Size | 1/4 |
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.
- NAS517-4-36 NAS 1/4-28 · 0.086 in · Flat countersunk · Steel
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Catalog data updated 2026-07-05. Report a data error