The Washer,flat, cataloged under National Stock Number 5310-01-031-8370, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. Government technical data includes 16 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-031-8370 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Status | ACTIVE |
| Outside Left Corner Chamfer Angle | 45.0 DEGREES NOMINAL |
| Overall Diameter | 1.375 INCHES NOMINAL IN |
| Inside Right Corner Chamfer Angle | 45.0 DEGREES NOMINAL |
| Hardness Rating | 27.0 ROCKWELL C MINIMUM OR 35.0 ROCKWELL C MAXIMUM |
| Criticality Code Justification | ZZZW |
| Cross-Sectional Shape Style | RECTANGULAR |
| Inside Left Corner Chamfer Angle | 45.0 DEGREES NOMINAL |
| Outside Right Corner Chamfer Angle | 45.0 DEGREES NOMINAL |
| Departure From Cited Document | AS DIFFERENTIATED BY SPECIAL QUALITY CONTROL TESTING FOR MK 48 TORPEDO |
| Color | BLACK OVERALL |
| Surface Treatment | OXIDE FILM OVERALL |
| Peripheral Shape Style | ROUND |
| Material | STEEL COMP 4140 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.564 INCHES MINIMUM AND 0.568 INCHES MAXIMUM IN |
| Thickness | 0.187 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 |
| Reference | Meaning |
|---|---|
| 2508735 | 3/9 Design control — primary reference Navair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier |
NSN 5310-01-031-8370 is a Washer,flat, classified under FSC 5310, Nuts and Washers. Status: active.
Key specifications for 5310-01-031-8370: Outside Left Corner Chamfer Angle: 45.0 DEGREES NOMINAL; Overall Diameter: 1.375 INCHES NOMINAL IN; Inside Right Corner Chamfer Angle: 45.0 DEGREES NOMINAL; Hardness Rating: 27.0 ROCKWELL C MINIMUM OR 35.0 ROCKWELL C MAXIMUM. 16 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.