The Washer,flat, cataloged under National Stock Number 5310-01-623-1778, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Specialty Washer Co of South Carolina Inc. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Item Name | Washer,flat |
| FSC / FSG | 5310 — Nuts and Washers (FSG 53) |
| Manufacturers | Specialty Washer Co of South Carolina Inc (CAGE 1P230) |
| Parameter | Value |
|---|---|
| NSN | 5310-01-623-1778 |
| Primary Part Number | PT891030 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Specialty Washer Co of South Carolina Inc |
| Status | ACTIVE |
| 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 |
|---|---|
| PT891030 PRIMARY | Specialty Washer Co of South Carolina Inc (USA) |
| Reference | Meaning |
|---|---|
| 7647281 | 7/2 Vendor item drawing reference Naval Sea Systems Command |
| PT891030 | 3/9 Design control — primary reference Phoenix Specialty Mfg Co Inc Modern Washer Co Div |
NSN 5310-01-623-1778 is a Washer,flat, manufactured by Specialty Washer Co of South Carolina Inc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-623-1778 has 1 manufacturer part number on file: PT891030 (Specialty Washer Co of South Carolina Inc).
2 possible matches (shared part number, not a government interchangeability claim): 5430-01-623-5090, 4730-01-623-5844. Verify interchangeability with system specifications before substitution.
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.