The Washer,flat, cataloged under National Stock Number 5310-01-133-4871, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Knight Aerospace Products, 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-133-4871 |
| Primary Part Number | 1000B40445M |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Knight Aerospace Products, Inc. |
| Status | ACTIVE |
| Width Across Flats | 2.000 INCHES NOMINAL IN |
| Cross-Sectional Shape Style | RECTANGULAR |
| Peripheral Shape Style | SQUARE |
| Material | STEEL COMP M1020 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.437 INCHES NOMINAL IN |
| Thickness | 0.250 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 |
|---|---|
| 1000B40445M PRIMARY | Knight Aerospace Products, Inc. (USA) |
| 91128A031 | Mcmaster-Carr Supply Co (USA) |
| Reference | Meaning |
|---|---|
| 1000B40445M | 5/9 Secondary reference Page Avjet Support Equipment Corp |
NSN 5310-01-133-4871 is a Washer,flat, manufactured by Knight Aerospace Products, Inc., classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-133-4871 has 2 manufacturer part numbers on file: 1000B40445M (Knight Aerospace Products, Inc.), 91128A031 (Mcmaster-Carr Supply Co).
Key specifications for 1000B40445M: Width Across Flats: 2.000 INCHES NOMINAL IN; Cross-Sectional Shape Style: RECTANGULAR; Peripheral Shape Style: SQUARE; Material: STEEL COMP M1020 OVERALL. 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.