The Washer,flat, cataloged under National Stock Number 5310-00-959-0791, 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 11 specifications, cited from the U.S. Government catalog. The record lists 3 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 5310-00-959-0791 |
| Primary Part Number | 525721 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney |
| Status | ACTIVE |
| Surface Finish | 63.0 MICROINCHES BOTTOM |
| Surface Finish | 63.0 MICROINCHES TOP |
| Overall Diameter | 0.570 INCHES MINIMUM AND 0.580 INCHES MAXIMUM IN |
| Heat Treatment | COLD ROLLED |
| Material Document and Classification | AMS 5518 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Peripheral Shape Style | ROUND |
| Material | STEEL COMP 301 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.339 INCHES MINIMUM AND 0.349 INCHES MAXIMUM IN |
| Thickness | 0.045 INCHES MINIMUM AND 0.055 INCHES MAXIMUM IN |
| 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 |
|---|---|
| 525721 | Alinabal Holdings Corporation Div Engineered Products Group (USA) |
| 525721 | Enjet Aero Manchester Llc (USA) |
| 525721 PRIMARY | Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney (USA) |
| Reference | Meaning |
|---|---|
| 525721 | 5/9 Secondary reference Turbo Power & Marine System Inc Sub of United Technologies Corp |
NSN 5310-00-959-0791 is a Washer,flat, manufactured by Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-00-959-0791 has 3 manufacturer part numbers on file: 525721 (Alinabal Holdings Corporation Div Engineered Products Group), 525721 (Enjet Aero Manchester Llc), 525721 (Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney).
1 possible match (shared part number, not a government interchangeability claim): 7025-01-656-3724. Verify interchangeability with system specifications before substitution.
Key specifications for 525721: Surface Finish: 63.0 MICROINCHES BOTTOM; Surface Finish: 63.0 MICROINCHES TOP; Overall Diameter: 0.570 INCHES MINIMUM AND 0.580 INCHES MAXIMUM IN; Heat Treatment: COLD ROLLED. 11 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.