The Nut,plain,extended Washer,double, cataloged under National Stock Number 5310-00-660-3044, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney. Government technical data includes 12 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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.
| Item Name | Nut,plain,extended Washer,double |
| FSC / FSG | 5310 — Nuts and Washers (FSG 53) |
| Manufacturers | Howmet Global Fastening Systems Inc (CAGE 15653); Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney (CAGE 77445) |
| Parameter | Value |
|---|---|
| NSN | 5310-00-660-3044 |
| Primary Part Number | 356137 |
| Item Name | Nut,plain,extended Washer,double |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney |
| Status | ACTIVE |
| Washer Outside Diameter | 0.491 INCHES NOMINAL IN |
| Width Across Flats | 0.4345 INCHES NOMINAL IN |
| Thread Series | UNF |
| Washer Thickness | 0.070 INCHES NOMINAL IN |
| Material Document and Classification | AMS 6322 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.312 INCHES IN |
| Surface Treatment | CADMIUM OVERALL |
| Nut Style | DOUBLE HEXAGON |
| Thread Class | 3B |
| Thread Quantity Per Inch | 24 |
| 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 5310-00-660-3044 is a Nut,plain,extended Washer,double, manufactured by Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-00-660-3044 has 2 manufacturer part numbers on file: 356137 (Howmet Global Fastening Systems Inc), 356137 (Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney).
Key specifications for 356137: Overall Height: 0.375 INCHES NOMINAL IN; Washer Outside Diameter: 0.491 INCHES NOMINAL IN; Width Across Flats: 0.4345 INCHES NOMINAL IN; Thread Series: UNF. 12 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.