The Washer,flat, cataloged under National Stock Number 5310-00-780-1818, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Honeywell International Inc. Dba Honeywell International Div Aerospace - Tempe (west Warner Road). Government technical data includes 8 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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 | 5310-00-780-1818 |
| Primary Part Number | 311581 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Honeywell International Inc. Dba Honeywell International Div Aerospace - Tempe (west Warner Road) |
| Status | ACTIVE |
| Overall Diameter | 0.561 INCHES MINIMUM AND 0.562 INCHES MAXIMUM IN |
| Material Document and Classification | MIL-A-5059 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Peripheral Shape Style | ROUND |
| Material | STEEL CORROSION RESISTING OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.100 INCHES MINIMUM AND 0.110 INCHES MAXIMUM IN |
| Thickness | 0.020 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 |
| Part Number | Manufacturer |
|---|---|
| 311581 PRIMARY | Honeywell International Inc. Dba Honeywell International Div Aerospace - Tempe (west Warner Road) (USA) |
| Reference | Meaning |
|---|---|
| 311581 | 5/9 Secondary reference U.S. Government activity |
NSN 5310-00-780-1818 is a Washer,flat, manufactured by Honeywell International Inc. Dba Honeywell International Div Aerospace - Tempe (west Warner Road), classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-00-780-1818 has 1 manufacturer part number on file: 311581 (Honeywell International Inc. Dba Honeywell International Div Aerospace - Tempe (west Warner Road)).
2 possible matches (shared part number, not a government interchangeability claim): 4920-01-109-0900, 6650-01-177-0632. Verify interchangeability with system specifications before substitution.
Key specifications for 311581: Overall Diameter: 0.561 INCHES MINIMUM AND 0.562 INCHES MAXIMUM IN; Material Document and Classification: MIL-A-5059 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL; Cross-Sectional Shape Style: RECTANGULAR; 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.