The Switch,lock,ignition, cataloged under National Stock Number 2920-01-595-2140, is classified within Federal Supply Class 2920 (Engine Electrical System Components, Nonaircraft) of the Engine Accessories group. The manufacturer of record is Cole Hersee Company. Government technical data includes 8 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 | 2920-01-595-2140 |
| Primary Part Number | M550 |
| Item Name | Switch,lock,ignition |
| FSC / FSG | 2920 / 29 — Engine Electrical System Components, Nonaircraft |
| Manufacturer | Cole Hersee Company |
| Status | ACTIVE |
| Bushing Length | 13.46 MILLIMETERS NOMINAL MM |
| Body Diameter | 36.57 MILLIMETERS NOMINAL MM |
| Switch Functional Positions | OFF AND IGNITION AND START |
| Inclosure Type | FULLY INCLOSED |
| Body Style | BUSHING MOUNTED |
| Mounting Method | SCREW |
| Body Length | 74.16 MILLIMETERS NOMINAL MM |
| Terminal Type and Quantity | 2 SCREW |
| 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 |
|---|---|
| M550 PRIMARY | Cole Hersee Company (USA) |
NSN 2920-01-595-2140 is a Switch,lock,ignition, manufactured by Cole Hersee Company, classified under FSC 2920, Engine Electrical System Components, Nonaircraft. Status: active.
NSN 2920-01-595-2140 has 1 manufacturer part number on file: M550 (Cole Hersee Company).
1 possible match (shared part number, not a government interchangeability claim): 5331-01-688-6842. Verify interchangeability with system specifications before substitution.
Key specifications for M550: Bushing Length: 13.46 MILLIMETERS NOMINAL MM; Body Diameter: 36.57 MILLIMETERS NOMINAL MM; Switch Functional Positions: OFF AND IGNITION AND START; Inclosure Type: FULLY INCLOSED. 8 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.