The Washer,flat, cataloged under National Stock Number 5310-00-978-7918, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. Government technical data includes 10 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 5310-00-978-7918 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Status | ACTIVE |
| Overall Diameter | 0.495 INCHES MINIMUM AND 0.520 INCHES MAXIMUM IN |
| Hardness Rating | 110.0 ROCKWELL R NOMINAL |
| Material Document and Classification | MIL-M-20693 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Minimum Tensile Strength | 7000 POUNDS PER SQUARE INCH LBS |
| Peripheral Shape Style | ROUND |
| Material | PLASTIC POLYHEXAMETHYLENE AMIDE OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.255 INCHES MINIMUM AND 0.275 INCHES MAXIMUM IN |
| Thickness | 0.084 INCHES MINIMUM AND 0.104 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 |
| Reference | Meaning |
|---|---|
| NAS1515H4H | 3/2 Design control — primary reference U.S. Government activity |
NSN 5310-00-978-7918 is a Washer,flat, classified under FSC 5310, Nuts and Washers. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 5310-01-628-8835. Verify interchangeability with system specifications before substitution.
Key specifications for 5310-00-978-7918: Overall Diameter: 0.495 INCHES MINIMUM AND 0.520 INCHES MAXIMUM IN; Hardness Rating: 110.0 ROCKWELL R NOMINAL; Material Document and Classification: MIL-M-20693 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL; Cross-Sectional Shape Style: RECTANGULAR. 10 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.