The Impeller,fan,axial, cataloged under National Stock Number 4140-01-181-8747, is classified within Federal Supply Class 4140 (Fans, Air Circulators, and Blower Equipment) of the Refrigeration, AC, and Air Circulating Equipment 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 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4140-01-181-8747 |
| Primary Part Number | 505551-604 |
| Item Name | Impeller,fan,axial |
| FSC / FSG | 4140 / 41 — Fans, Air Circulators, and Blower Equipment |
| Manufacturer | Fm Af, Llc Dba American Fan Company |
| Status | ACTIVE |
| Style Designator | ROUNDED TIP |
| Attachment Method | KEYWAY AND SETSCREW |
| Diameter | 18.965 INCHES MINIMUM AND 18.970 INCHES MAXIMUM IN |
| Blade Quantity | 23 |
| Hub Location | CENTER |
| Material | ALUMINUM ALLOY OVERALL |
| 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 |
|---|---|
| FF12990 PIECE 3 | Fm Af, Llc Dba American Fan Company (USA) |
| 505551-604 PRIMARY | Fm Af, Llc Dba American Fan Company (USA) |
| Reference | Meaning |
|---|---|
| 1389339-1 | 5/9 Secondary reference Fm Af, Llc Dba American Fan Company |
| 50551-604 | 3/9 Design control — primary reference Fm Af, Llc Dba American Fan Company |
NSN 4140-01-181-8747 is a Impeller,fan,axial, manufactured by Fm Af, Llc Dba American Fan Company, classified under FSC 4140, Fans, Air Circulators, and Blower Equipment. Status: active.
NSN 4140-01-181-8747 has 2 manufacturer part numbers on file: FF12990 PIECE 3 (Fm Af, Llc Dba American Fan Company), 505551-604 (Fm Af, Llc Dba American Fan Company).
Key specifications for 505551-604: Style Designator: ROUNDED TIP; Attachment Method: KEYWAY AND SETSCREW; Diameter: 18.965 INCHES MINIMUM AND 18.970 INCHES MAXIMUM IN; Blade Quantity: 23. 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.