The Washer,flat, cataloged under National Stock Number 5310-01-253-4445, 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 9 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. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-253-4445 |
| Primary Part Number | 5544138-6 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Overall Diameter | 0.620 INCHES MINIMUM AND 0.640 INCHES MAXIMUM IN |
| Heat Treatment | COLD ROLLED |
| Material Document and Classification | ASTM A568 ASSN STD ALL MATERIAL RESPONSES OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Peripheral Shape Style | ROUND |
| Material | STEEL COMP 1008 OR STEEL COMP 1009 OR STEEL COMP 1010 OR STEEL COMP 1012 OR STEEL COMP 1015 OR STEEL COMP 1016 OR STEEL COMP 1017 OR STEEL COMP 1018 OR STEEL COMP 1019 OR STEEL COMP 1020 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.276 INCHES MINIMUM AND 0.296 INCHES MAXIMUM IN |
| Thickness | 0.051 INCHES MINIMUM AND 0.080 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 |
| Part Number | Manufacturer |
|---|---|
| 5544138-6 PRIMARY | Naval Sea Systems Command (USA) |
NSN 5310-01-253-4445 is a Washer,flat, manufactured by Naval Sea Systems Command, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-253-4445 has 1 manufacturer part number on file: 5544138-6 (Naval Sea Systems Command).
Key specifications for 5544138-6: Overall Diameter: 0.620 INCHES MINIMUM AND 0.640 INCHES MAXIMUM IN; Heat Treatment: COLD ROLLED; Material Document and Classification: ASTM A568 ASSN STD ALL MATERIAL RESPONSES OVERALL; Cross-Sectional Shape Style: RECTANGULAR. 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.