The Nut,self-Locking,extended Washer, cataloged under National Stock Number 5310-00-431-0629, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Esna, Llc. Government technical data includes 15 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 5310-00-431-0629 |
| Primary Part Number | LH9756-4K |
| Item Name | Nut,self-Locking,extended Washer |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Esna, Llc |
| Status | ACTIVE |
| Washer Outside Diameter | 0.430 INCHES MAXIMUM IN |
| Width Across Flats | 0.305 INCHES MINIMUM AND 0.313 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | AMS 2400 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| Thread Series | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Hardness Rating | 39.0 ROCKWELL C MINIMUM AND 46.0 ROCKWELL C MAXIMUM |
| Washer Thickness | 0.047 INCHES MINIMUM AND 0.057 INCHES MAXIMUM IN |
| Material Document and Classification | AMS 6322 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.250 INCHES IN |
| Locking Feature | PREVAILING TORQUE ALL METAL DESIGN |
| Surface Treatment | CADMIUM OVERALL |
| Nut Style | DOUBLE HEXAGON |
| Thread Class | 3BG |
| Thread Quantity Per Inch | 28 |
| Material | STEEL COMP 8740 OVERALL |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
NSN 5310-00-431-0629 is a Nut,self-Locking,extended Washer, manufactured by Esna, Llc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-00-431-0629 has 2 manufacturer part numbers on file: LH9756-4K (Esna, Llc), 3016549 (Pratt & Whitney Canada Corp Div Pratt & Whitney Canada Corp.).
Key specifications for LH9756-4K: Overall Height: 0.313 INCHES MINIMUM AND 0.328 INCHES MAXIMUM IN; Washer Outside Diameter: 0.430 INCHES MAXIMUM IN; Width Across Flats: 0.305 INCHES MINIMUM AND 0.313 INCHES MAXIMUM IN; Surface Treatment Document and Classification: AMS 2400 ASSN STD SINGLE TREATMENT RESPONSE OVERALL. 15 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.