The Washer,flat, cataloged under National Stock Number 5310-01-263-3840, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Fm Af, Llc Dba American Fan Company. Government technical data includes 6 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-263-3840 |
| Primary Part Number | B5W-28829-20 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Fm Af, Llc Dba American Fan Company |
| Status | ACTIVE |
| Overall Diameter | 1.750 INCHES NOMINAL IN |
| Cross-Sectional Shape Style | RECTANGULAR |
| Peripheral Shape Style | ROUND |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.8125 INCHES NOMINAL IN |
| Thickness | 0.0625 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 |
|---|---|
| B5W-28829-20 PRIMARY | Fm Af, Llc Dba American Fan Company (USA) |
| Reference | Meaning |
|---|---|
| 5W-28829-20 | 5/9 Secondary reference New Philadelphia Fan Co Buffalo Forge Marine Fans |
| R1-11662 PC 47 | C/1 Advisory reference — outside the item-of-supply concept Fm Af, Llc Dba American Fan Company |
| 5W-28829-20 | 5/9 Secondary reference Fm Af, Llc Dba American Fan Company |
NSN 5310-01-263-3840 is a Washer,flat, manufactured by Fm Af, Llc Dba American Fan Company, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-263-3840 has 1 manufacturer part number on file: B5W-28829-20 (Fm Af, Llc Dba American Fan Company).
Key specifications for B5W-28829-20: Overall Diameter: 1.750 INCHES NOMINAL IN; Cross-Sectional Shape Style: RECTANGULAR; Peripheral Shape Style: ROUND; Center Hole Shape Style: ROUND. 6 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.