The Heating Element,electrical,immer, cataloged under National Stock Number 4520-00-032-1780, is classified within Federal Supply Class 4520 (Space and Water Heating Equipment) of the Plumbing, Heating, and Waste Disposal group. The manufacturer of record is Chromalox Inc Dba Chromalox Precision Heat and Control, Inc. Government technical data includes 25 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4520-00-032-1780 |
| Primary Part Number | 139838 |
| Item Name | Heating Element,electrical,immer |
| FSC / FSG | 4520 / 45 — Space and Water Heating Equipment |
| Manufacturer | Chromalox Inc Dba Chromalox Precision Heat and Control, Inc |
| Status | ACTIVE |
| Phase | SINGLE SINGLE VOLTAGE |
| Frequency in Hertz | 60.0 |
| Terminal Quantity | 4 |
| Length | 24.875 INCHES NOMINAL IN |
| Voltage in Volts and Current Type | 120.0 AC SINGLE VOLTAGE |
| Body Style | TUBULAR, SCREW TYPE |
| Maximum Wattage Rating in Watts | 3000.0 SINGLE VOLTAGE |
| Mounting Facility Length | 1.000 INCHES NOMINAL IN |
| Element Connection Style | TERMINAL SCREW |
| Effective Heating Length | 24.875 INCHES NOMINAL IN |
| Terminal Box Environmental Protection | STANDARD |
| Mounting Method Style | SCREW PLUG OR BUSHING TYPE MOUNTING FACILITY |
| Nominal Thread Size | 0.164 INCHES SCREW IN |
| Nominal Thread Size | 2.000 INCHES MOUNTING FACILITY IN |
| Heat Quantity | 1 |
| Watt Density Rating | 23.0 PER SQUARE INCH SINGLE VOLTAGE |
| Element Radiation Spectrum | NONINFRARED |
| Material | NICKEL AND CHROMIUM RESISTANCE WIRE |
| Material | MICA RESISTANCE WIRE EMBEDDING/SUPPORT INSULATION |
| Material | STEEL SHEATH |
| Thread Series Designator | NPT MOUNTING FACILITY |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) SCREW |
| Thread Quantity | 32.0 PER INCH SCREW |
| Thread Quantity | 11.5 PER INCH MOUNTING FACILITY |
| Element Quantity | 2 |
| 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 |
|---|---|
| 139838 PRIMARY | Chromalox Inc Dba Chromalox Precision Heat and Control, Inc (USA) |
| MTO-230A-120V | Chromalox Inc Dba Chromalox Precision Heat and Control, Inc (USA) |
| Reference | Meaning |
|---|---|
| MT0230 | 5/9 Secondary reference Chromalox Inc Dba Chromalox Precision Heat and Control, Inc |
NSN 4520-00-032-1780 is a Heating Element,electrical,immer, manufactured by Chromalox Inc Dba Chromalox Precision Heat and Control, Inc, classified under FSC 4520, Space and Water Heating Equipment. Status: active.
NSN 4520-00-032-1780 has 2 manufacturer part numbers on file: 139838 (Chromalox Inc Dba Chromalox Precision Heat and Control, Inc), MTO-230A-120V (Chromalox Inc Dba Chromalox Precision Heat and Control, Inc).
Key specifications for 139838: Phase: SINGLE SINGLE VOLTAGE; Frequency in Hertz: 60.0; Terminal Quantity: 4; Length: 24.875 INCHES NOMINAL IN. 25 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.