The Washer,flat, cataloged under National Stock Number 5310-01-155-4309, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Dutton-Lainson Company. Government technical data includes 8 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 5310-01-155-4309 |
| Primary Part Number | 404163 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Dutton-Lainson Company |
| Status | ACTIVE |
| Overall Diameter | 1.307 INCHES MINIMUM AND 1.312 INCHES MAXIMUM IN |
| Cross-Sectional Shape Style | RECTANGULAR |
| Surface Treatment | CHROMATE OVERALL |
| Peripheral Shape Style | ROUND |
| Material | STEEL COMP 1008 OR STEEL COMP 1010 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.628 INCHES MINIMUM AND 0.632 INCHES MAXIMUM IN |
| Thickness | 0.179 INCHES NOMINAL IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
NSN 5310-01-155-4309 is a Washer,flat, manufactured by Dutton-Lainson Company, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-155-4309 has 2 manufacturer part numbers on file: 2AA621 (Oshkosh Defense Llc), 404163 (Dutton-Lainson Company).
1 possible match (shared part number, not a government interchangeability claim): 6610-01-445-9580. Verify interchangeability with system specifications before substitution.
Key specifications for 404163: Overall Diameter: 1.307 INCHES MINIMUM AND 1.312 INCHES MAXIMUM IN; Cross-Sectional Shape Style: RECTANGULAR; Surface Treatment: CHROMATE OVERALL; Peripheral Shape Style: ROUND. 8 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.