PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

49-21Relay,electromagnetic

Keysight Technologies Inc · NSN 5945-00-821-2494 · FSC 5945 · No Item Name Available
Verified by PartsTable
NSN 5945-00-821-2494 — this item is cataloged by the U.S. Government under National Stock Number 5945-00-821-2494. Primary manufacturer part number: 49-21.
Features
  • Relay,electromagnetic — FSC 5945
  • Environmental Protection: HERMETIC
  • Duty Type: CONTINUOUS
  • Pile-Up Main Contact Form Arrangement: 1C
  • Criticality Code Justification: FEAT
  • Winding DC Resistance Rating: 2.0 KILOHMS NOMINAL SINGLE WINDING
  • Terminal Type and Quantity: 5 PIN ALL FUNCTIONS
  • Main Contact Maximum Voltage Rating in Volts: 28.0 DC
Applications
  • Circuit control and protection
  • Equipment power management
  • Signal routing
General Description

The Relay,electromagnetic, cataloged under National Stock Number 5945-00-821-2494, 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 Keysight Technologies Inc. Government technical data includes 13 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 8 commercial cross-references from 5 manufacturers, enabling identification through both NSN and commercial part number lookups. 6 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN5945-00-821-2494
Primary Part Number49-21
Item NameRelay,electromagnetic
FSC / FSG5945 / 59 — No Item Name Available
ManufacturerKeysight Technologies Inc
StatusCANCELLED
Environmental ProtectionHERMETIC
Duty TypeCONTINUOUS
Pile-Up Main Contact Form Arrangement1C
Criticality Code JustificationFEAT
Winding DC Resistance Rating2.0 KILOHMS NOMINAL SINGLE WINDING
Terminal Type and Quantity5 PIN ALL FUNCTIONS
Main Contact Maximum Voltage Rating in Volts28.0 DC
Mounting Facility Type and Quantity1 PLUG-IN TERMINAL(S) SINGLE MOUNTING FACILITY
Overall Diameter0.750 INCHES NOMINAL IN
Coil Quantity1
Operating Voltage Rating and Type at Specified Temp28.0 VOLTS DC 25 DEG CELSIUS SINGLE WINDING
Winding Quantity1
Nominal Operating Current Rating and Type10.0 MILLIAMPERES DC SINGLE WINDING
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 6
5930-00-105-82531557 INTERCHANGEABLE
Switch,toggle
Hubbell Incorporated (delaware) Dba Wiring Device-Kellems Division
5905-00-135-2134RCS1K0 INTERCHANGEABLE
Resistor,variable,wire Wound,non
Ohmite Holding, L.l.c. Dba Ohmite Manufacturing
5360-00-350-750510A3381 INTERCHANGEABLE
Spring,helical,compression
Napco International Llc Dba Napco International Inc
5120-01-087-7672GS19525-1 INTERCHANGEABLE
Tool,installer,seal
Hamilton Sundstrand Corporation Dba Collins Aerospace
5305-01-195-49974921 INTERCHANGEABLE
Screw,externally Relieved Body
Husco International Inc
6515-01-425-4677 INTERCHANGEABLE
Cpr Protective Mask
Cross-Reference Index
Part NumberManufacturer
0490-0010 Hewlett-Packard Company Dba HP (USA)
10366460 Us Army Aviation and Missile Command (USA)
49-21 Keysight Technologies, Inc. (USA)
49-21 Hewlett-Packard Company Dba HP (USA)
SM-4107SPECIAL Te Connectivity Corporation (USA)
0490-0010 Keysight Technologies, Inc. (USA)
49-21 PRIMARY Keysight Technologies Inc (USA)
0490-0010 Keysight Technologies Inc (USA)
Related Parts
5930-00-105-8253INTERCHANGEABLE
SWITCH,TOGGLE
1557
5905-00-135-2134INTERCHANGEABLE
RESISTOR,VARIABLE,WIRE WOUND,NON
RCS1K0
5360-00-350-7505INTERCHANGEABLE
SPRING,HELICAL,COMPRESSION
10A3381
5120-01-087-7672INTERCHANGEABLE
TOOL,INSTALLER,SEAL
GS19525-1
5305-01-195-4997INTERCHANGEABLE
SCREW,EXTERNALLY RELIEVED BODY
4921
6515-01-425-4677INTERCHANGEABLE
CPR PROTECTIVE MASK

Frequently Asked Questions

What is NSN 5945-00-821-2494?

NSN 5945-00-821-2494 is a Relay,electromagnetic, manufactured by Keysight Technologies Inc, classified under FSC 5945 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 5945-00-821-2494?

NSN 5945-00-821-2494 has 8 cross-referenced part numbers: 0490-0010 (Hewlett-Packard Company Dba HP), 10366460 (Us Army Aviation and Missile Command), 49-21 (Keysight Technologies, Inc.), 49-21 (Hewlett-Packard Company Dba HP), SM-4107SPECIAL (Te Connectivity Corporation) and 3 more.

What NSN replaces 5945-00-821-2494?

There are 6 known substitutes for 5945-00-821-2494: 5930-00-105-8253, 5905-00-135-2134, 5360-00-350-7505 and 3 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 49-21?

Key specifications for 49-21: Environmental Protection: HERMETIC; Overall Length: 1.650 INCHES NOMINAL IN; Duty Type: CONTINUOUS; Pile-Up Main Contact Form Arrangement: 1C. 16 total characteristics are documented in the Federal Logistics Information System.

Is NSN 5945-00-821-2494 still in active supply?

NSN 5945-00-821-2494 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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