The Transformer,audio Frequency, cataloged under National Stock Number 5950-01-257-8288, is classified within Federal Supply Class 5950 (Coils and Transformers) of the Electrical and Electronic Equipment Components group. The manufacturer of record is Magnetika Inc. Government technical data includes 16 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5950-01-257-8288 |
| Primary Part Number | 0-21 |
| Item Name | Transformer,audio Frequency |
| FSC / FSG | 5950 / 59 — Coils and Transformers |
| Manufacturer | Magnetika Inc |
| Status | ACTIVE |
| Mounting Facility Quantity | 2 SINGLE GROUP |
| Inclosure Type | FULLY INCLOSED |
| Body Outside Diameter | 0.875 INCHES NOMINAL IN |
| Mounting Method | THREADED HOLE(S) SINGLE GROUP |
| Winding Function and Quantity | 1 PRIMARY AND 1 SECONDARY SINGLE COMPONENT |
| Impedance Rating in Ohms | 8.0 NOMINAL SINGLE COMPONENT SINGLE SECONDARY |
| Impedance Rating in Ohms | 2000.0 NOMINAL SINGLE COMPONENT SINGLE PRIMARY |
| Distance Between Mounting Facility Centers | 0.688 INCHES NOMINAL SINGLE MOUNTING FACILITY SINGLE CENTER GROUP IN |
| Nominal Thread Size | 0.086 INCHES SINGLE GROUP IN |
| Body Length | 1.188 INCHES NOMINAL IN |
| Winding Operating Current | 4.0 MILLIAMPERES DC MAXIMUM SINGLE COMPONENT SINGLE PRIMARY |
| Reliability Indicator | NOT ESTABLISHED |
| Frequency Rating | 100.0 HERTZ MINIMUM AND 40.0 KILOHERTZ MAXIMUM SINGLE COMPONENT |
| Primary to Secondary Turn Ratio | 1 TO 10 SINGLE COMPONENT |
| Terminal Type and Quantity | 5 TAB, SOLDER LUG |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) SINGLE GROUP |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 0-21 PRIMARY | Magnetika Inc (USA) |
| Reference | Meaning |
|---|---|
| 0-21 | 5/9 Secondary reference U.S. Government activity |
NSN 5950-01-257-8288 is a Transformer,audio Frequency, manufactured by Magnetika Inc, classified under FSC 5950, Coils and Transformers. Status: active.
NSN 5950-01-257-8288 has 1 manufacturer part number on file: 0-21 (Magnetika Inc).
3 possible matches (shared part number, not a government interchangeability claim): 3940-01-458-4438, 4220-01-487-6439, 8145-01-524-7273. Verify interchangeability with system specifications before substitution.
Key specifications for 0-21: Mounting Facility Quantity: 2 SINGLE GROUP; Inclosure Type: FULLY INCLOSED; Body Outside Diameter: 0.875 INCHES NOMINAL IN; Mounting Method: THREADED HOLE(S) SINGLE GROUP. 16 specifications are documented in the U.S. Government catalog.
Possible hazard — SDS may be required (DLA HMIC P). 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.