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NAS1802-4-20
Machine Screw
Description
Fastener Length: 1-9/32", Thread: 1/4-28, Thread Length: 1-1/4", hex head
Specifications
| Fastener Length | Between 1.234 inches and 1.281 inches |
|---|---|
| Head Height | Between 0.125 inches and 0.140 inches |
| Head Style | Hexagon Head |
| Internal Drive Style | Cross recess type 1 |
| Material | Iron |
| Min. Tensile Strength (psi) | 160000 pounds per square inch |
| Screw Material | Iron alloy 660 |
| Screw Material Specification | Ams 5731 assn standard single material response or ams 5737 assn standard single material response |
| Screw Surface Treatment | Passivate |
| Screw Surface Treatment Specification | Qq-p-35 federal specification single treatment response |
| Specification Data | 80205-nas1802 professional/industrial association standard |
| Thread Class | 3a |
| Thread Diameter | 0.250 |
| Thread Direction | Right-hand |
| Thread Length | Between 1.132 inches and 1.250 inches |
| Thread Qty | 28 |
| Thread Qty Per Inch (tpi) | 28 |
| Thread Series | UNJF |
| Thread Series Designator | Unjf (fine thread with external controlled root radius) |
| Thread Size | 1/4 |
| Width Between Flats | Between 0.367 inches and 0.376 inches |
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.
- NAS1801-4-20 NAS 1/4-28 · 1.28 in · Hexagon Head · Steel
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Catalog data updated 2026-07-05. Report a data error