The Shaft,shouldered, cataloged under National Stock Number 3040-00-451-8780, is classified within Federal Supply Class 3040 (Miscellaneous Power Transmission Equipment) of the Mechanical Power Transmission Equipment group. The manufacturer of record is Oeco, Llc Dba Pacific Scientific Oeco. Government technical data includes 14 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. 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 | 3040-00-451-8780 |
| Primary Part Number | 78684 |
| Item Name | Shaft,shouldered |
| FSC / FSG | 3040 / 30 — Miscellaneous Power Transmission Equipment |
| Manufacturer | Oeco, Llc Dba Pacific Scientific Oeco |
| Status | ACTIVE |
| Surface Finish | 63.0 MICROINCHES |
| Step Quantity | 2 |
| First End Diameter | 0.7874 INCHES NOMINAL IN |
| Second End Diameter | 0.7874 INCHES NOMINAL IN |
| Largest Step Diameter | 1.100 INCHES NOMINAL IN |
| Second End Spline Minor Diameter | 0.3952 INCHES MINIMUM AND 0.4049 INCHES MAXIMUM IN |
| First End Style | PLAIN |
| Criticality Code Justification | MATT |
| Second End Spline Major Diameter | 0.4970 INCHES MINIMUM AND 0.5000 INCHES MAXIMUM IN |
| End Similarity | NOT IDENTICAL |
| Second End Spline Quantity | 11 |
| Second End Style | SPLINED (STRAIGHT) |
| Material | STEEL COMP 416 |
| Second End Spline Length | 0.625 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 | Y |
| Part Number | Manufacturer |
|---|---|
| 78684 PRIMARY | Oeco, Llc Dba Pacific Scientific Oeco (USA) |
NSN 3040-00-451-8780 is a Shaft,shouldered, manufactured by Oeco, Llc Dba Pacific Scientific Oeco, classified under FSC 3040, Miscellaneous Power Transmission Equipment. Status: active.
NSN 3040-00-451-8780 has 1 manufacturer part number on file: 78684 (Oeco, Llc Dba Pacific Scientific Oeco).
1 possible match (shared part number, not a government interchangeability claim): 5340-01-127-4503. Verify interchangeability with system specifications before substitution.
Key specifications for 78684: Surface Finish: 63.0 MICROINCHES; Step Quantity: 2; First End Diameter: 0.7874 INCHES NOMINAL IN; Second End Diameter: 0.7874 INCHES NOMINAL IN. 14 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.