PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

663999Transformer,power

Lockheed Martin Corporation Div Rms - Mitchel Field · NSN 5950-00-648-6737 · FSC 5950 · No Item Name Available
Verified by PartsTable
NSN 5950-00-648-6737 — this item is cataloged by the U.S. Government under National Stock Number 5950-00-648-6737. Primary manufacturer part number: 663999.
Features
  • Transformer,power — FSC 5950
  • Winding Operating Voltage: 23.00 AC VOLTS NOMINAL AND 115.00 AC VOLTS NOMINAL SINGLE COMPONENT SINGLE PRIMARY
  • Reliability Indicator: NOT ESTABLISHED
  • Center to Center Distance Between Mounting Facilities Parallel to Length: 1.500 INCHES NOMINAL SINGLE MOUNTING FACILITY SINGLE CENTER GROUP IN
  • Nominal Thread Size: 0.138 INCHES SINGLE GROUP IN
  • Body Length: 2.078 INCHES MAXIMUM IN
  • Winding Operating Current: 10.0 MILLIAMPERES AC MAXIMUM SINGLE COMPONENT FIRST SECONDARY
  • Frequency Rating: 400.0 HERTZ NOMINAL SINGLE COMPONENT
Applications
  • Industrial maintenance and repair
  • Government and military logistics
  • Equipment overhaul and refurbishment
General Description

The Transformer,power, cataloged under National Stock Number 5950-00-648-6737, is classified within Federal Supply Class 5950 (No Item Name Available) of the Electrical and Electronic Equipment Components group. The primary manufacturer of record is Lockheed Martin Corporation Div Rms - Mitchel Field. Government technical data includes 21 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 4 commercial cross-references from 4 manufacturers, enabling identification through both NSN and commercial part number lookups. 7 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN5950-00-648-6737
Primary Part Number663999
Item NameTransformer,power
FSC / FSG5950 / 59 — No Item Name Available
ManufacturerLockheed Martin Corporation Div Rms - Mitchel Field
StatusACTIVE
Winding Operating Voltage23.00 AC VOLTS NOMINAL AND 115.00 AC VOLTS NOMINAL SINGLE COMPONENT SINGLE PRIMARY
Reliability IndicatorNOT ESTABLISHED
Center to Center Distance Between Mounting Facilities Parallel to Length1.500 INCHES NOMINAL SINGLE MOUNTING FACILITY SINGLE CENTER GROUP IN
Nominal Thread Size0.138 INCHES SINGLE GROUP IN
Body Length2.078 INCHES MAXIMUM IN
Winding Operating Current10.0 MILLIAMPERES AC MAXIMUM SINGLE COMPONENT FIRST SECONDARY
Frequency Rating400.0 HERTZ NOMINAL SINGLE COMPONENT
Center to Center Distance Between Mounting Facilities Parallel to Width1.188 INCHES NOMINAL SINGLE MOUNTING FACILITY SINGLE CENTER GROUP IN
Maximum Operating Temp105.0 CELSIUS DEGC
Body Height2.203 INCHES MAXIMUM IN
Inclosure TypeHERMETICALLY SEALED
Winding Operating Current600.0 MILLIAMPERES AC MAXIMUM SINGLE COMPONENT SECOND SECONDARY
Body Width1.766 INCHES MAXIMUM IN
Winding Function and Quantity1 PRIMARY AND 2 SECONDARY SINGLE COMPONENT
Terminal Type and Quantity8 TAB, SOLDER LUG
Mounting MethodTHREADED STUD(S) SINGLE GROUP
Winding Operating Voltage6.30 AC VOLTS NOMINAL SINGLE COMPONENT SECOND SECONDARY
Mounting Facility Quantity4 SINGLE GROUP
Thread Series DesignatorUNIFIED NATIONAL COARSE (UNC) SINGLE GROUP
Input-Output Phase RelationshipSINGLE PHASE TO SINGLE PHASE SINGLE COMPONENT
Winding Operating Voltage600.00 AC VOLTS NOMINAL SINGLE COMPONENT FIRST SECONDARY
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 7
5985-00-455-44878491B-003 INTERCHANGEABLE
Attenuator,fixed
Keysight Technologies Inc
5315-00-899-313338903 INTERCHANGEABLE
Pin,straight,headless
Lourdes Industries, Inc.
4820-00-924-0533N38903 INTERCHANGEABLE
Seat,valve
Leslie Controls, Inc. Dba Leslie Controls Inc
6680-01-121-014438903 INTERCHANGEABLE
Transmitter,liquid Quantity
Setra Systems, Inc. Dba Gems Sensors
5910-01-364-105838903 INTERCHANGEABLE
Capacitor,fixed,plastic Dielectr
Transistor Devices Inc Div Astrodyne Tdi High Power Business Unit
5940-01-371-5268 INTERCHANGEABLE
Terminal,lug
3950-01-399-105138903 INTERCHANGEABLE
Pulley,whelped Groove
Ingersoll-Rand Company Dba Ingersoll-Rand Div Tool & Hoist Division
Cross-Reference Index
Part NumberManufacturer
T59756 Thordarson Inc (USA)
PEI 4046 Precision Electronics, Inc (USA)
663999 PRIMARY Lockheed Martin Corporation Div Rms - Mitchel Field (USA)
38903 Freed Transformer Co (USA)
Related Parts
5985-00-455-4487INTERCHANGEABLE
ATTENUATOR,FIXED
8491B-003
5315-00-899-3133INTERCHANGEABLE
PIN,STRAIGHT,HEADLESS
38903
4820-00-924-0533INTERCHANGEABLE
SEAT,VALVE
N38903
6680-01-121-0144INTERCHANGEABLE
TRANSMITTER,LIQUID QUANTITY
38903
5910-01-364-1058INTERCHANGEABLE
CAPACITOR,FIXED,PLASTIC DIELECTR
38903
5940-01-371-5268INTERCHANGEABLE
TERMINAL,LUG
3950-01-399-1051INTERCHANGEABLE
PULLEY,WHELPED GROOVE
38903

Frequently Asked Questions

What is NSN 5950-00-648-6737?

NSN 5950-00-648-6737 is a Transformer,power, manufactured by Lockheed Martin Corporation Div Rms - Mitchel Field, classified under FSC 5950 (No Item Name Available). Status: active.

What are the part numbers for NSN 5950-00-648-6737?

NSN 5950-00-648-6737 has 4 cross-referenced part numbers: T59756 (Thordarson Inc), PEI 4046 (Precision Electronics, Inc), 663999 (Lockheed Martin Corporation Div Rms - Mitchel Field), 38903 (Freed Transformer Co).

What NSN replaces 5950-00-648-6737?

There are 7 known substitutes for 5950-00-648-6737: 5985-00-455-4487, 5315-00-899-3133, 4820-00-924-0533 and 4 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 663999?

Key specifications for 663999: Winding Operating Voltage: 23.00 AC VOLTS NOMINAL AND 115.00 AC VOLTS NOMINAL SINGLE COMPONENT SINGLE PRIMARY; Reliability Indicator: NOT ESTABLISHED; Center to Center Distance Between Mounting Facilities Parallel to Length: 1.500 INCHES NOMINAL SINGLE MOUNTING FACILITY SINGLE CENTER GROUP IN; Nominal Thread Size: 0.138 INCHES SINGLE GROUP IN. 21 total characteristics are documented in the Federal Logistics Information System.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
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