The Washer,flat, cataloged under National Stock Number 5310-00-357-1981, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. Government technical data includes 11 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-00-357-1981 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Status | ACTIVE |
| Width Across Flats | 0.580 INCHES MINIMUM AND 0.640 INCHES MAXIMUM IN |
| Length | 0.580 INCHES MINIMUM AND 0.640 INCHES MAXIMUM IN |
| Material Document and Classification | MIL-S-5059 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-6721 MIL SPEC 2ND MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Specification/standard Data | 80205-NAS1401 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| Surface Treatment | PASSIVATE OVERALL |
| Peripheral Shape Style | RECTANGULAR |
| Material | STEEL OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.310 INCHES MINIMUM AND 0.338 INCHES MAXIMUM IN |
| Thickness | 0.160 INCHES NOMINAL 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 |
|---|---|
| NAS1401-5C5 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5310-00-357-1981 is a Washer,flat, classified under FSC 5310, Nuts and Washers. Status: active.
Key specifications for 5310-00-357-1981: Width Across Flats: 0.580 INCHES MINIMUM AND 0.640 INCHES MAXIMUM IN; Length: 0.580 INCHES MINIMUM AND 0.640 INCHES MAXIMUM IN; Material Document and Classification: MIL-S-5059 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-6721 MIL SPEC 2ND MATERIAL RESPONSE OVERALL; Cross-Sectional Shape Style: RECTANGULAR. 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.