The Washer,lock, cataloged under National Stock Number 5310-01-256-9731, 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9 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5310-01-256-9731 |
| Item Name | Washer,lock |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Status | ACTIVE |
| Surface Treatment Document and Classification | ASTM B633 TYPE 2 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| Hardness Rating | 89.0 ROCKWELL B MINIMUM AND 94.0 ROCKWELL B MAXIMUM |
| Style Designator | FLAT INTERNAL TEETH |
| Material Document and Classification | 66 FED STD ALL MATERIAL RESPONSES OVERALL |
| Outside Diameter | 0.365 INCHES MINIMUM AND 0.381 INCHES MAXIMUM IN |
| Material Thickness | 0.020 INCHES MINIMUM AND 0.025 INCHES MAXIMUM IN |
| Surface Treatment | ZINC AND CHROMATE OVERALL |
| Material | STEEL COMP 1050 OR STEEL COMP 1551 OR STEEL COMP 1552 OR STEEL COMP 1053 OR STEEL COMP 1054 OR STEEL COMP 1055 OR STEEL COMP 1059 OR STEEL COMP 1060 OR STEEL COMP 1561 OR STEEL COMP 1062 OR STEEL COMP 1064 OVERALL |
| Hole Diameter | 0.195 INCHES MINIMUM AND 0.204 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 |
|---|---|
| MS51413-4 | 2/2 Government specification standardization U.S. Government activity |
| FF-W-100 | 4/1 Identification reference U.S. Government activity |
NSN 5310-01-256-9731 is a Washer,lock, classified under FSC 5310, Nuts and Washers. Status: active.
Key specifications for 5310-01-256-9731: Surface Treatment Document and Classification: ASTM B633 TYPE 2 ASSN STD SINGLE TREATMENT RESPONSE OVERALL; Hardness Rating: 89.0 ROCKWELL B MINIMUM AND 94.0 ROCKWELL B MAXIMUM; Style Designator: FLAT INTERNAL TEETH; Material Document and Classification: 66 FED STD ALL MATERIAL RESPONSES OVERALL. 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.