The Washer,flat, cataloged under National Stock Number 5310-01-481-2281, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Oshkosh Defense Llc. Government technical data includes 5 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-481-2281 |
| Primary Part Number | 4MB975 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Oshkosh Defense Llc |
| Status | ACTIVE |
| Overall Diameter | 0.250 INCHES NOMINAL IN |
| Cross-Sectional Shape Style | RECTANGULAR |
| Peripheral Shape Style | ROUND |
| Material | STEEL CORROSION RESISTING OVERALL |
| Center Hole Shape Style | ROUND |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
NSN 5310-01-481-2281 is a Washer,flat, manufactured by Oshkosh Defense Llc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-481-2281 has 2 manufacturer part numbers on file: 4MB975 (Oshkosh Defense Llc), 101370 (Curt Manufacturing Llc).
1 possible match (shared part number, not a government interchangeability claim): 5331-01-583-6547. Verify interchangeability with system specifications before substitution.
Key specifications for 4MB975: Overall Diameter: 0.250 INCHES NOMINAL IN; Cross-Sectional Shape Style: RECTANGULAR; Peripheral Shape Style: ROUND; Part Name Assigned by Controlling Agency: WASHER, PL, A, SST, 0.250. 5 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.