The Washer,lock, cataloged under National Stock Number 5310-00-261-7123, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. Government technical data includes 7 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 5310-00-261-7123 |
| Item Name | Washer,lock |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Status | ACTIVE |
| Style Designator | SPLIT HELICAL-RIGHT HAND |
| Material Document and Classification | QQ-S-763 COND B FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Outside Diameter | 0.591 INCHES NOMINAL IN |
| Material Thickness | 0.078 INCHES NOMINAL IN |
| Nondefinitive Spec/std Data | C CLASS AND 2 STYLE |
| Material | STEEL COMP 302 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 |
|---|---|
| FFW84CLASSCSTYLE2 | 4/1 Identification reference U.S. Government activity |
NSN 5310-00-261-7123 is a Washer,lock, classified under FSC 5310, Nuts and Washers. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 5310-00-551-0226. Verify interchangeability with system specifications before substitution.
Key specifications for 5310-00-261-7123: Style Designator: SPLIT HELICAL-RIGHT HAND; Material Document and Classification: QQ-S-763 COND B FED SPEC SINGLE MATERIAL RESPONSE OVERALL; Outside Diameter: 0.591 INCHES NOMINAL IN; Material Thickness: 0.078 INCHES NOMINAL IN. 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.