The Washer,flat, cataloged under National Stock Number 5310-00-656-0290, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Honeywell Intl Inc Defense Avionics Systems. Government technical data includes 10 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 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 | 5310-00-656-0290 |
| Primary Part Number | 1302111-1 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Honeywell Intl Inc Defense Avionics Systems |
| Status | ACTIVE |
| Overall Diameter | 0.375 INCHES NOMINAL IN |
| Heat Treatment | ANNEALED |
| Material Document and Classification | MIL-S-5059 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Surface Treatment | PASSIVATE OVERALL |
| Peripheral Shape Style | ROUND |
| Material | STEEL COMP 302 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.119 INCHES MINIMUM AND 0.124 INCHES MAXIMUM IN |
| Thickness | 0.078 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 5310-00-656-0290 is a Washer,flat, manufactured by Honeywell Intl Inc Defense Avionics Systems, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-00-656-0290 has 2 manufacturer part numbers on file: 1302111-1 (Honeywell Intl Inc Defense Avionics Systems), 9054170 (Us Army Aviation and Missile Command).
1 possible match (shared part number, not a government interchangeability claim): 7610-01-599-2528. Verify interchangeability with system specifications before substitution.
Key specifications for 1302111-1: Overall Diameter: 0.375 INCHES NOMINAL IN; Heat Treatment: ANNEALED; Material Document and Classification: MIL-S-5059 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL; Cross-Sectional Shape Style: RECTANGULAR. 10 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.