The Washer,flat, cataloged under National Stock Number 5310-01-140-1580, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Steward Machine Co Inc. 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 5310-01-140-1580 |
| Primary Part Number | 590-351 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Steward Machine Co Inc |
| Status | ACTIVE |
| Surface Finish | 32.0 MICROINCHES BOTTOM |
| Surface Finish | 32.0 MICROINCHES TOP |
| Overall Diameter | 2.750 INCHES NOMINAL IN |
| Material Document and Classification | AISI ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Peripheral Shape Style | ROUND |
| Material | STEEL COMP 1020 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 1.5025 INCHES MINIMUM AND 1.5035 INCHES MAXIMUM IN |
| Thickness | 0.215 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 |
|---|---|
| 590-351 PRIMARY | Steward Machine Co Inc (USA) |
| 590-352AP PRIMARY | Acme Products & Engineering Inc (USA) |
| Reference | Meaning |
|---|---|
| 590-352 | 5/9 Secondary reference Hardie-Tynes Co., Inc. |
| 60-701 PIECE 352 | 3/9 Design control — primary reference Hardie-Tynes Co., Inc. |
NSN 5310-01-140-1580 is a Washer,flat, manufactured by Steward Machine Co Inc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-140-1580 has 2 manufacturer part numbers on file: 590-351 (Steward Machine Co Inc), 590-352AP (Acme Products & Engineering Inc).
1 possible match (shared part number, not a government interchangeability claim): 5310-01-151-5601. Verify interchangeability with system specifications before substitution.
Key specifications for 590-351: Surface Finish: 32.0 MICROINCHES BOTTOM; Surface Finish: 32.0 MICROINCHES TOP; Overall Diameter: 2.750 INCHES NOMINAL IN; Material Document and Classification: AISI ASSN STD SINGLE MATERIAL RESPONSE OVERALL. 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.