The Shaft Assembly,flexible, cataloged under National Stock Number 1680-00-540-1930, is classified within Federal Supply Class 1680 (Miscellaneous Aircraft Accessories and Components) of the Aircraft Components and Accessories group. The manufacturer of record is Eaton Aerospace Llc Dba Eaton Inoac Div Fuel & Motion Control Systems Division. Government technical data includes 29 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 1680-00-540-1930 |
| Primary Part Number | B1671-21 |
| Item Name | Shaft Assembly,flexible |
| FSC / FSG | 1680 / 16 — Miscellaneous Aircraft Accessories and Components |
| Manufacturer | Eaton Aerospace Llc Dba Eaton Inoac Div Fuel & Motion Control Systems Division |
| Status | ACTIVE |
| FSC Application Data | SHAFT INSTALLATION,TRAILING EDGE FLAP,AIRCRAFT |
| Width Across Flats | 0.750 INCHES NOMINAL BOTH ENDS IN |
| Spline Type | INVOLUTE BOTH ENDS |
| Cross Section Size and Location | 0.409 INCHES NOMINAL DIAMETER BOTH ENDS IN |
| End Overall Diameter | 0.875 INCHES NOMINAL BOTH ENDS IN |
| End Connection Type | THREADED INTERNAL BOTH ENDS |
| Spline Length | 0.275 INCHES NOMINAL BOTH ENDS IN |
| Thread Depth | 0.310 INCHES NOMINAL BOTH ENDS IN |
| Pitch Diameter | 0.250 INCHES NOMINAL BOTH ENDS IN |
| Spline Major Diameter | 0.303 INCHES NOMINAL BOTH ENDS IN |
| Thread Location | INTERNAL BOTH ENDS |
| Core Diameter | 0.276 INCHES NOMINAL IN |
| Thread Direction | RIGHT-HAND BOTH ENDS |
| Spline Pressure Angle in Deg | 14.5 BOTH ENDS |
| Spline Quantity | 12 BOTH ENDS |
| Casing Length Between Ferrules | 11.910 INCHES NOMINAL IN |
| Core Rotation Direction | CLOCKWISE OR COUNTERCLOCKWISE |
| Shank Outside Diameter | 0.4375 INCHES NOMINAL BOTH ENDS IN |
| Core Removability | NONREMOVABLE |
| Core Overall Length | 12.8474 INCHES NOMINAL IN |
| Screw Thread Series Designator | UNS BOTH ENDS |
| Surface Treatment | CADMIUM CASING |
| Thread Class | 3B OR 2 BOTH ENDS |
| Minor Diameter | UNABLE TO DECODE |
| Wrenching Facility Type | HEXAGON BOTH ENDS |
| Material | STEEL CORE |
| Material | STEEL CASING |
| Casing Outside Diameter | 0.375 INCHES NOMINAL IN |
| Minimum Operating Radius | 2.500 INCHES IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL Q — CCL Item — Commerce Control List |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| B1671-21 PRIMARY | Eaton Aerospace Llc Dba Eaton Inoac Div Fuel & Motion Control Systems Division (USA) |
| Reference | Meaning |
|---|---|
| B1671-21 | 5/9 Secondary reference Eaton Motor Site |
| 669293-5 | 5/2 Secondary reference U.S. Government activity |
NSN 1680-00-540-1930 is a Shaft Assembly,flexible, manufactured by Eaton Aerospace Llc Dba Eaton Inoac Div Fuel & Motion Control Systems Division, classified under FSC 1680, Miscellaneous Aircraft Accessories and Components. Status: active.
NSN 1680-00-540-1930 has 1 manufacturer part number on file: B1671-21 (Eaton Aerospace Llc Dba Eaton Inoac Div Fuel & Motion Control Systems Division).
Key specifications for B1671-21: FSC Application Data: SHAFT INSTALLATION,TRAILING EDGE FLAP,AIRCRAFT; Width Across Flats: 0.750 INCHES NOMINAL BOTH ENDS IN; Spline Type: INVOLUTE BOTH ENDS; Cross Section Size and Location: 0.409 INCHES NOMINAL DIAMETER BOTH ENDS IN. 29 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.
NSN 1680-00-540-1930 has DEMIL Code Q. Demilitarization may be required before disposal or transfer to non-military entities.
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.