The Nut,self-Locking,extended Washer, cataloged under National Stock Number 5310-01-266-8401, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. Government technical data includes 16 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 5310-01-266-8401 |
| Item Name | Nut,self-Locking,extended Washer |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Status | ACTIVE |
| Lubrication | DRY FILM LUBRICANT |
| Washer Outside Diameter | 0.984 INCHES MINIMUM AND 1.024 INCHES MAXIMUM IN |
| Width Across Flats | 0.741 INCHES MINIMUM AND 0.752 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Series | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Washer Thickness | 0.084 INCHES NOMINAL IN |
| Material Document and Classification | AMS5737 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.625 INCHES IN |
| Specification/standard Data | 80205-1805 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| Locking Feature | PREVAILING TORQUE ALL METAL DESIGN |
| Surface Treatment | PASSIVATE OVERALL |
| Nut Style | DOUBLE HEXAGON |
| Thread Class | 3B |
| Thread Quantity Per Inch | 18 |
| Material | IRON ALLOY 660 OVERALL |
| 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 |
|---|---|
| NAS1805-10 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5310-01-266-8401 is a Nut,self-Locking,extended Washer, classified under FSC 5310, Nuts and Washers. Status: active.
Key specifications for 5310-01-266-8401: Lubrication: DRY FILM LUBRICANT; Overall Height: 0.625 INCHES MAXIMUM IN; Washer Outside Diameter: 0.984 INCHES MINIMUM AND 1.024 INCHES MAXIMUM IN; Width Across Flats: 0.741 INCHES MINIMUM AND 0.752 INCHES MAXIMUM IN. 16 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.