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NAS623-4-20
Machine Screw
Description
Fastener Length: 1-37/64", Thread: 1/4-28, Thread Length: 21/64", NAS623 series screw
Specifications
| Fastener Length | 1.551 inches minimum and 1.581 inches maximum |
|---|---|
| Hardness Rating | 36.0 rockwell c minimum and 40.0 rockwell c maximum |
| Head Diameter | 0.473 inches minimum and 0.492 inches maximum |
| Head Height | 0.162 inches minimum and 0.175 inches maximum |
| Head Style | Pan Head |
| Internal Drive Style | Cross recess type 1 |
| Length | 1 37/64 |
| Material | Steel |
| Min. Tensile Strength (psi) | 160000 pounds per square inch |
| Screw Material | Steel comp 4140 or steel comp e4340 or steel comp 8740 |
| Screw Material Specification | Mil-s-5626 mil spec 1st material response or mil-s-5000 mil spec 2nd material response or mil-s-6049 mil spec 3rd material response |
| Screw Surface Treatment | Cadmium and chromate |
| Screw Surface Treatment Specification | Qq-p-416 ty 2 cl 2 fed spec single treatment response |
| Specification Data | 80205-nas623 professional/industrial association standard |
| Thread Class | 3a |
| Thread Diameter | 0.250 |
| Thread Direction | Right-hand |
| Thread Length | 0.291 inches minimum and 0.341 inches maximum |
| Thread Qty | 28 |
| Thread Qty Per Inch (tpi) | 28 |
| Thread Series Designator | UNJF |
| 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.
- NAS1634-21 NAS 1/4-28 · 0.073 in · Pan Head · Steel
- NAS623-4-13 NAS 1/4-28 · 0.073 in · Pan Head · Steel
- NAS623-4-26 NAS 1/4-28 · 0.073 in · Pan Head · Steel
- NAS623-4-27 NAS 1/4-28 · 0.073 in · Pan Head · Steel
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Catalog data updated 2026-07-05. Report a data error