The Washer,flat, cataloged under National Stock Number 5310-01-031-8379, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Naval Sea Systems Command. Government technical data includes 12 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-031-8379 |
| Primary Part Number | 2498489-4 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Surface Treatment Document and Classification | QQ-P-416,TYPE 2,CLASS 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Overall Diameter | 0.489 INCHES MINIMUM AND 0.495 INCHES MAXIMUM IN |
| Hardness Rating | 27.0 ROCKWELL C MINIMUM AND 35.0 ROCKWELL C MAXIMUM |
| Criticality Code Justification | ZZZW |
| Cross-Sectional Shape Style | RECTANGULAR |
| Departure From Cited Document | AS DIFFERENTIATED BY SPECIAL QUALITY CONTROL TESTING FOR MK 48 TORPEDO |
| Surface Treatment | CADMIUM OVERALL |
| Peripheral Shape Style | ROUND |
| Material | STEEL COMP 4140H OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.314 INCHES MINIMUM AND 0.322 INCHES MAXIMUM IN |
| Thickness | 0.078 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 | Y |
| Part Number | Manufacturer |
|---|---|
| 2498489-4 PRIMARY | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| 2498489-4 | 5/9 Secondary reference Navair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier |
NSN 5310-01-031-8379 is a Washer,flat, manufactured by Naval Sea Systems Command, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-031-8379 has 1 manufacturer part number on file: 2498489-4 (Naval Sea Systems Command).
Key specifications for 2498489-4: Surface Treatment Document and Classification: QQ-P-416,TYPE 2,CLASS 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Overall Diameter: 0.489 INCHES MINIMUM AND 0.495 INCHES MAXIMUM IN; Hardness Rating: 27.0 ROCKWELL C MINIMUM AND 35.0 ROCKWELL C MAXIMUM; Criticality Code Justification: ZZZW. 12 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.