The Washer,flat, cataloged under National Stock Number 5310-01-643-2181, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is M.t. Davidson Company. 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 4 items share a part number with this NSN in the catalog (possible match — not a government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 | M.t. Davidson Company (CAGE 16062) |
| Parameter | Value |
|---|---|
| NSN | 5310-01-643-2181 |
| Primary Part Number | A3-021-0009 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | M.t. Davidson Company |
| 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 |
|---|---|
| A3-021-0009 PRIMARY | M.t. Davidson Company (USA) |
| Reference | Meaning |
|---|---|
| D3-433-0010 | D/9 Drawing number reference only M.t. Davidson Company |
| D3-433-0010-9 | C/1 Advisory reference — outside the item-of-supply concept M.t. Davidson Company |
NSN 5310-01-643-2181 is a Washer,flat, manufactured by M.t. Davidson Company, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-643-2181 has 1 manufacturer part number on file: A3-021-0009 (M.t. Davidson Company).
4 possible matches (shared part number, not a government interchangeability claim): 5330-01-643-2314, 5330-01-643-2377, 5330-01-643-2401. 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.