The Heating Element,electrical,nonim, cataloged under National Stock Number 4520-01-277-7481, 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 National Oilwell Varco Inc Dba National Oilwell. Government technical data includes 5 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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 | 4520-01-277-7481 |
| Primary Part Number | 21570 |
| Item Name | Heating Element,electrical,nonim |
| FSC / FSG | 4520 / 45 — Space and Water Heating Equipment |
| Manufacturer | National Oilwell Varco Inc Dba National Oilwell |
| Status | ACTIVE |
| Phase | SINGLE SINGLE VOLTAGE |
| Frequency in Hertz | 60.0 |
| Voltage in Volts and Current Type | 120.0 AC SINGLE VOLTAGE |
| Maximum Wattage Rating in Watts | 500.0 SINGLE VOLTAGE |
| Material | STEEL RESISTANCE WIRE |
| 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 |
|---|---|
| 21570 PRIMARY | National Oilwell Varco Inc Dba National Oilwell (USA) |
| Reference | Meaning |
|---|---|
| 21570 | 5/9 Secondary reference National Oil Well Dba Iec Baylor |
NSN 4520-01-277-7481 is a Heating Element,electrical,nonim, manufactured by National Oilwell Varco Inc Dba National Oilwell, classified under FSC 4520, Space and Water Heating Equipment. Status: active.
NSN 4520-01-277-7481 has 1 manufacturer part number on file: 21570 (National Oilwell Varco Inc Dba National Oilwell).
2 possible matches (shared part number, not a government interchangeability claim): 5330-01-422-5958, 6520-01-591-8071. Verify interchangeability with system specifications before substitution.
Key specifications for 21570: Phase: SINGLE SINGLE VOLTAGE; Frequency in Hertz: 60.0; Voltage in Volts and Current Type: 120.0 AC SINGLE VOLTAGE; Maximum Wattage Rating in Watts: 500.0 SINGLE VOLTAGE. 5 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.