The Washer,flat, cataloged under National Stock Number 5310-00-421-6667, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is The Boeing Company Div Defense. Government technical data includes 11 specifications, cited from the U.S. Government catalog. The record lists 4 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-00-421-6667 |
| Primary Part Number | 32-21137-51 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | The Boeing Company Div Defense |
| Status | ACTIVE |
| Width Across Flats | 3.000 INCHES NOMINAL IN |
| Length | 3.000 INCHES NOMINAL IN |
| Heat Treatment | AS FABRICATED |
| Material Document and Classification | MIL-S-6721 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Surface Treatment | SILVER OVERALL |
| Peripheral Shape Style | RECTANGULAR |
| Material | STEEL COMP 321 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.050 INCHES NOMINAL IN |
| Thickness | 0.050 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 |
|---|---|
| 32-21137-51 | Associated Aircraft Manufacturing & Sales, Inc. Dba Associated Aircraft Manufacturing & Sales Inc (USA) |
| 32-21137-51 | Derco Aerospace, Inc. Dba Derco Aerospace, Inc. a Lockheed Martin Company (USA) |
| 32-21137-51 PRIMARY | The Boeing Company Div Defense (USA) |
| 32-21137-51 | Kitco Llc (USA) |
NSN 5310-00-421-6667 is a Washer,flat, manufactured by The Boeing Company Div Defense, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-00-421-6667 has 4 manufacturer part numbers on file: 32-21137-51 (Associated Aircraft Manufacturing & Sales, Inc. Dba Associated Aircraft Manufacturing & Sales Inc), 32-21137-51 (Derco Aerospace, Inc. Dba Derco Aerospace, Inc. a Lockheed Martin Company), 32-21137-51 (The Boeing Company Div Defense), 32-21137-51 (Kitco Llc).
Key specifications for 32-21137-51: Width Across Flats: 3.000 INCHES NOMINAL IN; Length: 3.000 INCHES NOMINAL IN; Heat Treatment: AS FABRICATED; Material Document and Classification: MIL-S-6721 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL. 11 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.