The Washer,concave, cataloged under National Stock Number 5310-01-658-8831, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Howmet Global Fastening Systems Inc. Government technical data includes 7 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through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 5310-01-658-8831 |
| Primary Part Number | K39781-3 |
| Item Name | Washer,concave |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Howmet Global Fastening Systems Inc |
| Status | ACTIVE |
| Radius | 0.218 INCHES MINIMUM AND 0.238 INCHES MAXIMUM IN |
| Style Designator | CONCAVE |
| Outside Diameter | 0.339 INCHES MINIMUM AND 0.349 INCHES MAXIMUM IN |
| Recess Depth | 0.025 INCHES NOMINAL IN |
| Material Thickness | 0.058 INCHES MINIMUM AND 0.083 INCHES MAXIMUM IN |
| Material | STEEL COMP 8740 OVERALL |
| Hole Diameter | 0.200 INCHES MINIMUM AND 0.210 INCHES MAXIMUM 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 |
|---|---|
| 9487-0 | Esna, Llc (USA) |
| K39781-3 PRIMARY | Howmet Global Fastening Systems Inc (USA) |
| Reference | Meaning |
|---|---|
| LE153-0001 | D/9 Drawing number reference only The Boeing Company Div Legacy Am&m |
| LE153-0001-0003 | 5/9 Secondary reference Howmet Global Fastening Systems Inc |
| LE153-0001-0003 | 5/2 Secondary reference U.S. Government activity |
| LE153-0001-0003 | 7/2 Vendor item drawing reference The Boeing Company Div Legacy Am&m |
NSN 5310-01-658-8831 is a Washer,concave, manufactured by Howmet Global Fastening Systems Inc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-658-8831 has 2 manufacturer part numbers on file: 9487-0 (Esna, Llc), K39781-3 (Howmet Global Fastening Systems Inc).
1 possible match (shared part number, not a government interchangeability claim): 5310-01-659-0049. Verify interchangeability with system specifications before substitution.
Key specifications for K39781-3: Radius: 0.218 INCHES MINIMUM AND 0.238 INCHES MAXIMUM IN; Style Designator: CONCAVE; Outside Diameter: 0.339 INCHES MINIMUM AND 0.349 INCHES MAXIMUM IN; Recess Depth: 0.025 INCHES NOMINAL IN. 7 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.