The Nut,self-Locking,extended Washer, cataloged under National Stock Number 5310-01-121-2751, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Leonardo Spa Helicopters Division - Production Site. Government technical data includes 17 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-121-2751 |
| Primary Part Number | NAS1805-3 |
| Item Name | Nut,self-Locking,extended Washer |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Leonardo Spa Helicopters Division - Production Site |
| Status | ACTIVE |
| Lubrication | DRY FILM LUBRICANT |
| Washer Outside Diameter | 0.339 INCHES MAXIMUM IN |
| Width Across Flats | 0.243 INCHES MINIMUM AND 0.251 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Series | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Temp Rating | 450.0 FAHRENHEIT MAXIMUM DEGF |
| Washer Thickness | 0.015 INCHES NOMINAL IN |
| Material Document and Classification | AMS 5737 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.190 INCHES IN |
| Specification/standard Data | 80205-NAS1805 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 | 32 |
| 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 |
| Part Number | Manufacturer |
|---|---|
| NAS1805-3 | Leonardo Spa Helicopters Division - Production Site (ITA) |
| Reference | Meaning |
|---|---|
| NAS1805-3 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5310-01-121-2751 is a Nut,self-Locking,extended Washer, manufactured by Leonardo Spa Helicopters Division - Production Site, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-121-2751 has 1 manufacturer part number on file: NAS1805-3 (Leonardo Spa Helicopters Division - Production Site).
Key specifications for NAS1805-3: Lubrication: DRY FILM LUBRICANT; Overall Height: 0.190 INCHES MAXIMUM IN; Washer Outside Diameter: 0.339 INCHES MAXIMUM IN; Width Across Flats: 0.243 INCHES MINIMUM AND 0.251 INCHES MAXIMUM 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.