The Screw,close Tolerance, cataloged under National Stock Number 5305-01-421-1981, 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17 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-421-1981 |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Status | ACTIVE |
| Fastener Length | 1.513 INCHES MINIMUM AND 1.543 INCHES MAXIMUM IN |
| Thread Length | 0.403 INCHES MAXIMUM IN |
| Material Document and Classification | AMS 4928 ASSN STD SINGLE MATERIAL RESPONSE OR AMS 4967 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Specification/standard Data | 80205-NAS1581 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| Grip Length | 1.115 INCHES MINIMUM AND 1.125 INCHES MAXIMUM IN |
| Grip Diameter | 0.2490 INCHES MINIMUM AND 0.2495 INCHES MAXIMUM IN |
| Minimum Tensile Strength | 160000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | OFFSET CRUCIFORM (TORQUE SET) |
| Countersink Angle | 99.0 DEGREES MINIMUM AND 101.0 DEGREES MAXIMUM |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | TITANIUM ALLOY UNS R56400 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.3504 INCHES MINIMUM AND 0.3988 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 |
|---|---|
| NAS1581K4T18 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5305-01-421-1981 is a Screw,close Tolerance, classified under FSC 5305, Screws. Status: active.
Key specifications for 5305-01-421-1981: Fastener Length: 1.513 INCHES MINIMUM AND 1.543 INCHES MAXIMUM IN; Thread Length: 0.403 INCHES MAXIMUM IN; Material Document and Classification: AMS 4928 ASSN STD SINGLE MATERIAL RESPONSE OR AMS 4967 ASSN STD SINGLE MATERIAL RESPONSE OVERALL; Nominal Thread Diameter: 0.250 INCHES IN. 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.