The Screw,cap,socket Head, cataloged under National Stock Number 5305-01-490-1291, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. Government technical data includes 17 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-490-1291 |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Status | ACTIVE |
| Width Across Flats | 0.312 INCHES MINIMUM AND 0.316 INCHES MAXIMUM IN |
| Head Height | 0.368 INCHES MINIMUM AND 0.375 INCHES MAXIMUM IN |
| Fastener Length | 1.500 INCHES NOMINAL IN |
| Surface Treatment Document and Classification | ASTMB633-78, TYPE II ASSN STD ALL TREATMENT RESPONSES OVERALL |
| Thread Length | 1.500 INCHES NOMINAL IN |
| Material Document and Classification | ASTMA574 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.375 INCHES IN |
| Head Style | DEE CHAMFER |
| Thread Direction | RIGHT-HAND |
| Surface Treatment | ZINC AND CHROMATE OVERALL |
| Minimum Tensile Strength | 12400 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | HEXAGON |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 16 |
| Material | STEEL UNS K03104 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| Head Diameter | 0.550 INCHES MINIMUM AND 0.562 INCHES MAXIMUM IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| MS51484-18 | 2/2 Government specification standardization U.S. Government activity |
| 6510E71FN63 | 5/1 Secondary reference U.S. Government activity |
NSN 5305-01-490-1291 is a Screw,cap,socket Head, classified under FSC 5305, Screws. Status: active.
Key specifications for 5305-01-490-1291: Width Across Flats: 0.312 INCHES MINIMUM AND 0.316 INCHES MAXIMUM IN; Head Height: 0.368 INCHES MINIMUM AND 0.375 INCHES MAXIMUM IN; Fastener Length: 1.500 INCHES NOMINAL IN; Surface Treatment Document and Classification: ASTMB633-78, TYPE II ASSN STD ALL TREATMENT RESPONSES OVERALL. 17 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.