The Washer,flat, cataloged under National Stock Number 5310-01-491-0127, 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10 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 5310-01-491-0127 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Status | ACTIVE |
| Surface Treatment Document and Classification | QQ-P-416 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Overall Diameter | 1.620 INCHES NOMINAL IN |
| Hardness Rating | 38.0 ROCKWELL C MINIMUM AND 42.0 ROCKWELL C MAXIMUM |
| Cross-Sectional Shape Style | RECTANGULAR |
| Surface Treatment | CADMIUM OVERALL |
| Peripheral Shape Style | ROUND |
| Material | STEEL COMP 1074 OR STEEL COMP 1029 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.530 INCHES MINIMUM AND 0.560 INCHES MAXIMUM IN |
| Thickness | 0.113 INCHES MINIMUM AND 0.117 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 |
|---|---|
| 614572 | 3/9 Design control — primary reference Tbr Inc. |
NSN 5310-01-491-0127 is a Washer,flat, classified under FSC 5310, Nuts and Washers. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 7050-01-580-4767. Verify interchangeability with system specifications before substitution.
Key specifications for 5310-01-491-0127: Surface Treatment Document and Classification: QQ-P-416 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Overall Diameter: 1.620 INCHES NOMINAL IN; Hardness Rating: 38.0 ROCKWELL C MINIMUM AND 42.0 ROCKWELL C MAXIMUM; 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.