The Washer,lock, cataloged under National Stock Number 5310-00-820-6658, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. Government technical data includes 9 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-00-820-6658 |
| Item Name | Washer,lock |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Status | ACTIVE |
| Hardness Rating | 45.0 ROCKWELL C MINIMUM AND 53.0 ROCKWELL C MAXIMUM |
| Style Designator | SPLIT HELICAL-RIGHT HAND |
| Material Document and Classification | FED STD 66 FED STD SINGLE MATERIAL RESPONSE OVERALL |
| Outside Diameter | 0.575 INCHES NOMINAL IN |
| Material Thickness | 0.056 INCHES MINIMUM AND 0.066 INCHES MAXIMUM IN |
| Departure From Cited Designator | AS MODIFIED BY MATERIAL |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Material | STEEL OVERALL |
| Hole Diameter | 0.319 INCHES MINIMUM AND 0.333 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 |
|---|---|
| 23MS35337-7 | 3/2 Design control — primary reference U.S. Government activity |
| MS35337-7 | 4/1 Identification reference U.S. Government activity |
NSN 5310-00-820-6658 is a Washer,lock, classified under FSC 5310, Nuts and Washers. Status: active.
Key specifications for 5310-00-820-6658: Hardness Rating: 45.0 ROCKWELL C MINIMUM AND 53.0 ROCKWELL C MAXIMUM; Style Designator: SPLIT HELICAL-RIGHT HAND; Material Document and Classification: FED STD 66 FED STD SINGLE MATERIAL RESPONSE OVERALL; Outside Diameter: 0.575 INCHES NOMINAL IN. 9 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.