The Washer,flat, cataloged under National Stock Number 5310-01-525-0656, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Mcmaster-Carr Supply Co. Government technical data includes 7 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. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-525-0656 |
| Primary Part Number | 98017A640 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Mcmaster-Carr Supply Co |
| Status | ACTIVE |
| Overall Diameter | 0.438 INCHES NOMINAL IN |
| Cross-Sectional Shape Style | RECTANGULAR |
| Peripheral Shape Style | ROUND |
| Material | STEEL CORROSION RESISTING OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.203 INCHES NOMINAL IN |
| Thickness | 0.057 INCHES MINIMUM AND 0.069 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 |
|---|---|
| 98017A640 PRIMARY | Mcmaster-Carr Supply Co (USA) |
| 0209782 FIND 18 | Niwc Pacific San Diego Navy Erp Dba Naval Information Warfare Center Pacific Div Naval Information Warfare Center Pacific (USA) |
NSN 5310-01-525-0656 is a Washer,flat, manufactured by Mcmaster-Carr Supply Co, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-525-0656 has 2 manufacturer part numbers on file: 98017A640 (Mcmaster-Carr Supply Co), 0209782 FIND 18 (Niwc Pacific San Diego Navy Erp Dba Naval Information Warfare Center Pacific Div Naval Information Warfare Center Pacific).
Key specifications for 98017A640: Overall Diameter: 0.438 INCHES NOMINAL IN; Cross-Sectional Shape Style: RECTANGULAR; Peripheral Shape Style: ROUND; Material: STEEL CORROSION RESISTING OVERALL. 7 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.