The Washer,special, cataloged under National Stock Number 5310-01-666-2199, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. Government technical data includes 1 specification, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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.
| Parameter | Value |
|---|---|
| NSN | 5310-01-666-2199 |
| Item Name | Washer,special |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Status | ACTIVE |
| Criticality Code Justification | FEAT |
| 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 |
|---|---|
| NASM21299 | 5/1 Secondary reference U.S. Government activity |
| MS21299 | 5/9 Secondary reference U.S. Government activity |
| MS21299C20K | 3/2 Design control — primary reference U.S. Government activity |
NSN 5310-01-666-2199 is a Washer,special, classified under FSC 5310, Nuts and Washers. Status: active.
2 possible matches (shared part number, not a government interchangeability claim): 5310-01-713-4379, 5310-01-713-4385. Verify interchangeability with system specifications before substitution.
Key specifications for 5310-01-666-2199: Criticality Code Justification: FEAT; Special Features: CRITICAL APPLICATION ITEM (CAI); End Item Identification: CH-53K AIRCRAFT. 1 specification is 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.