The Nut,self-Locking,extended Washer, cataloged under National Stock Number 5310-01-181-1124, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Howmet Global Fastening Systems Inc. Government technical data includes 8 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 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-181-1124 |
| Primary Part Number | H39557-4 |
| Item Name | Nut,self-Locking,extended Washer |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Howmet Global Fastening Systems Inc |
| Status | ACTIVE |
| Washer Outside Diameter | 0.406 INCHES NOMINAL IN |
| Width Across Flats | 0.309 INCHES NOMINAL IN |
| Thread Series | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.250 INCHES IN |
| Nut Style | HEXAGON |
| Thread Class | 3B |
| Material | STEEL CORROSION RESISTING 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 5310-01-181-1124 is a Nut,self-Locking,extended Washer, manufactured by Howmet Global Fastening Systems Inc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-181-1124 has 2 manufacturer part numbers on file: 1149P08 (General Electric Company), H39557-4 (Howmet Global Fastening Systems Inc).
1 possible match (shared part number, not a government interchangeability claim): 5310-01-450-2863. Verify interchangeability with system specifications before substitution.
Key specifications for H39557-4: Overall Height: 0.212 INCHES NOMINAL IN; Washer Outside Diameter: 0.406 INCHES NOMINAL IN; Width Across Flats: 0.309 INCHES NOMINAL IN; Thread Series: UNIFIED NATIONAL JOINT FINE (UNJF). 8 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.