The Screw,cap,socket Head, cataloged under National Stock Number 5305-01-321-3571, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. Government technical data includes 25 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5305-01-321-3571 |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Status | ACTIVE |
| Width Across Flats | 0.375 INCHES MINIMUM AND 0.379 INCHES MAXIMUM IN |
| Head Height | 0.430 INCHES MINIMUM AND 0.437 INCHES MAXIMUM IN |
| Fastener Length | 4.920 INCHES MINIMUM AND 5.000 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | AMS 2411 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 1.375 INCHES MINIMUM IN |
| Hardness Rating | 33.0 ROCKWELL C MINIMUM AND 42.0 ROCKWELL C MAXIMUM OVERALL |
| Hole Configuration Style | ROUND INTERNAL HEXAGON |
| Material Document and Classification | AMS 5731 ASSN STD SINGLE MATERIAL RESPONSE OR AMS 5737 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.4375 INCHES IN |
| Head Style | FLAT CHAMFER |
| Thread Direction | RIGHT-HAND |
| Specification/standard Data | 80205-NAS1351 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| Surface Treatment | SILVER OVERALL |
| Precious Material and Location | OVERALL SILVER |
| Minimum Tensile Strength | 160000 POUNDS PER SQUARE INCH LBS |
| Minimum Yield Strength | 120000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | HEXAGON |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 20 |
| Material | IRON ALLOY 660 OVERALL |
| Hole Quantity | 6 |
| Thread Series Designator | UNRF |
| Hole Type | DRILLED |
| Hole Diameter | 0.061 INCHES MINIMUM AND 0.067 INCHES MAXIMUM IN |
| Head Diameter | 0.642 INCHES MINIMUM AND 0.656 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 |
|---|---|
| 20409-003 FIND 38 | 5/9 Secondary reference Sargent Aerospace & Defense, Llc Dba Sargent Controls & Aerospace Div Sargent Controls & Aerospace |
| NAS1351N7H80S | 3/2 Design control — primary reference U.S. Government activity |
NSN 5305-01-321-3571 is a Screw,cap,socket Head, classified under FSC 5305, Screws. Status: active.
Key specifications for 5305-01-321-3571: Width Across Flats: 0.375 INCHES MINIMUM AND 0.379 INCHES MAXIMUM IN; Head Height: 0.430 INCHES MINIMUM AND 0.437 INCHES MAXIMUM IN; Fastener Length: 4.920 INCHES MINIMUM AND 5.000 INCHES MAXIMUM IN; Surface Treatment Document and Classification: AMS 2411 ASSN STD SINGLE TREATMENT RESPONSE OVERALL. 25 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.