The Washer,flat, cataloged under National Stock Number 5310-01-391-2789, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Ontic Engineering & Manufacturing, Inc Dba Ontic Us. 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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.
| Item Name | Washer,flat |
| FSC / FSG | 5310 — Nuts and Washers (FSG 53) |
| Manufacturers | Ontic Engineering & Manufacturing, Inc Dba Ontic Us (CAGE 45934) |
| Parameter | Value |
|---|---|
| NSN | 5310-01-391-2789 |
| Primary Part Number | 584823 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Ontic Engineering & Manufacturing, Inc Dba Ontic Us |
| 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 |
|---|---|
| 584823 PRIMARY | Ontic Engineering & Manufacturing, Inc Dba Ontic Us (USA) |
| Reference | Meaning |
|---|---|
| 584823 | 5/9 Secondary reference Hamilton Sundstrand Corporation Dba Collins Aerospace |
NSN 5310-01-391-2789 is a Washer,flat, manufactured by Ontic Engineering & Manufacturing, Inc Dba Ontic Us, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-391-2789 has 1 manufacturer part number on file: 584823 (Ontic Engineering & Manufacturing, Inc Dba Ontic Us).
2 possible matches (shared part number, not a government interchangeability claim): 6515-01-428-4199, 2920-01-554-3242. 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.