PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

255ARELAYRelay,electromagnetic

American Telephone and Telegraph Co · NSN 5945-00-188-5631 · FSC 5945 · No Item Name Available
Verified by PartsTable
NSN 5945-00-188-5631 — this item is cataloged by the U.S. Government under National Stock Number 5945-00-188-5631. Primary manufacturer part number: 255ARELAY.
Features
  • Relay,electromagnetic — FSC 5945
  • Center to Center Distance Between Mounting Facilities Parallel to Length: 2.188 INCHES NOMINAL SINGLE MOUNTING FACILITY IN
  • Duty Type: CONTINUOUS
  • Winding DC Resistance Rating: 136.0 OHMS NOMINAL SINGLE WINDING
  • Thread Class: 2A SINGLE MOUNTING FACILITY A
  • Nominal Thread Size: 0.250 INCHES SINGLE MOUNTING FACILITY IN
  • Thread Series Designator: UNIFIED NATIONAL COARSE (UNC) SINGLE MOUNTING FACILITY
  • Terminal Type and Quantity: 4 SCREW ENERGIZING ELEMENT
Applications
  • Circuit control and protection
  • Equipment power management
  • Signal routing
General Description

The Relay,electromagnetic, cataloged under National Stock Number 5945-00-188-5631, is classified within Federal Supply Class 5945 (No Item Name Available) of the Electrical and Electronic Equipment Components group. The primary manufacturer of record is American Telephone and Telegraph Co. Government technical data includes 18 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 8 commercial cross-references from 4 manufacturers, enabling identification through both NSN and commercial part number lookups. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN5945-00-188-5631
Primary Part Number255ARELAY
Item NameRelay,electromagnetic
FSC / FSG5945 / 59 — No Item Name Available
ManufacturerAmerican Telephone and Telegraph Co
StatusCANCELLED
Center to Center Distance Between Mounting Facilities Parallel to Length2.188 INCHES NOMINAL SINGLE MOUNTING FACILITY IN
Duty TypeCONTINUOUS
Winding DC Resistance Rating136.0 OHMS NOMINAL SINGLE WINDING
Thread Class2A SINGLE MOUNTING FACILITY A
Nominal Thread Size0.250 INCHES SINGLE MOUNTING FACILITY IN
Thread Series DesignatorUNIFIED NATIONAL COARSE (UNC) SINGLE MOUNTING FACILITY
Terminal Type and Quantity4 SCREW ENERGIZING ELEMENT
Mounting Facility PatternRECTANGULAR SINGLE MOUNTING FACILITY
Main Contact Load Current Rating at Maximum Rated Voltage2.0 AMPERES DC RESISTIVE LOAD
Mounting Facility Type and Quantity4 THREADED HOLE(S) SINGLE MOUNTING FACILITY
Terminal Type and Quantity3 SCREW CONTACTS
Features ProvidedPOLARIZED
Center to Center Distance Between Mounting Facilities Parallel to Width2.188 INCHES NOMINAL SINGLE MOUNTING FACILITY IN
Nominal Operating Current Rating and Type5.0 MILLIAMPERES DC ALL WINDINGS
Main Contact Maximum Voltage Rating in Volts110.0 DC
Winding Quantity2
Environmental ProtectionDUSTPROOF
Coil Quantity1
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 12
6625-00-034-0540 INTERCHANGEABLE
Vibroground
5905-00-108-6155M0DEL260-2K0HMP0RM5PCT INTERCHANGEABLE
Resistor,variable,wire Wound,non
Samarius Precision Instruments, Inc. Dba Samarius Precision Instruments
5905-00-108-6486 INTERCHANGEABLE
Resistor,variable,wire Wound,non
5905-00-112-4166 INTERCHANGEABLE
Resistor,variable,wire Wound,non
6625-00-155-6030 INTERCHANGEABLE
Ohmmeter
5910-00-281-0641 INTERCHANGEABLE
Capacitor,fixed,paper Dielectric
5330-00-350-7494314A INTERCHANGEABLE
Gasket
Saylor-Beall Manufacturing Company
4030-00-428-1058 INTERCHANGEABLE
Swivel
5930-00-504-6071 INTERCHANGEABLE
Switch,toggle
5905-00-655-3726 INTERCHANGEABLE
Resistor,variable,wire Wound,non
Cross-Reference Index
Part NumberManufacturer
255ARELAY American Telephone and Telegraph Co (USA)
255RELAY At and T Corp (USA)
255A At and T Corp (USA)
255A American Telephone and Telegraph Co (USA)
314A American Telephone and Telegraph Co (USA)
255A Lucent Technologies Inc Corporate Headquarters (USA)
314A Lucent Technologies Inc Corporate Headquarters (USA)
F2255 Codalex Ltd (CAN)
Related Parts
6625-00-034-0540INTERCHANGEABLE
VIBROGROUND
5905-00-108-6155INTERCHANGEABLE
RESISTOR,VARIABLE,WIRE WOUND,NON
M0DEL260-2K0HMP0RM5PCT
5905-00-108-6486INTERCHANGEABLE
RESISTOR,VARIABLE,WIRE WOUND,NON
5905-00-112-4166INTERCHANGEABLE
RESISTOR,VARIABLE,WIRE WOUND,NON
6625-00-155-6030INTERCHANGEABLE
OHMMETER
5910-00-281-0641INTERCHANGEABLE
CAPACITOR,FIXED,PAPER DIELECTRIC
5330-00-350-7494INTERCHANGEABLE
GASKET
314A
4030-00-428-1058INTERCHANGEABLE
SWIVEL
5930-00-504-6071INTERCHANGEABLE
SWITCH,TOGGLE
5905-00-655-3726INTERCHANGEABLE
RESISTOR,VARIABLE,WIRE WOUND,NON
6720-00-663-1006INTERCHANGEABLE
CAMERA,STILL PICTURE
6625-00-788-0919INTERCHANGEABLE
VOLTMETER
314A

Frequently Asked Questions

What is NSN 5945-00-188-5631?

NSN 5945-00-188-5631 is a Relay,electromagnetic, manufactured by American Telephone and Telegraph Co, classified under FSC 5945 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 5945-00-188-5631?

NSN 5945-00-188-5631 has 8 cross-referenced part numbers: 255ARELAY (American Telephone and Telegraph Co), 255RELAY (At and T Corp), 255A (At and T Corp), 255A (American Telephone and Telegraph Co), 314A (American Telephone and Telegraph Co) and 3 more.

What NSN replaces 5945-00-188-5631?

There are 12 known substitutes for 5945-00-188-5631: 6625-00-034-0540, 5905-00-108-6155, 5905-00-108-6486 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 255ARELAY?

Key specifications for 255ARELAY: Overall Width: 2.680 INCHES NOMINAL IN; Center to Center Distance Between Mounting Facilities Parallel to Length: 2.188 INCHES NOMINAL SINGLE MOUNTING FACILITY IN; Duty Type: CONTINUOUS; Winding DC Resistance Rating: 136.0 OHMS NOMINAL SINGLE WINDING. 22 total characteristics are documented in the Federal Logistics Information System.

Is NSN 5945-00-188-5631 still in active supply?

NSN 5945-00-188-5631 is currently cancelled. Check with the Defense Logistics Agency for current availability and authorized substitutes.

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