PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

42558Relay,thermal

Cooper Industries Inc Cooper Distribution Equipment Div · NSN 5945-00-977-5850 · FSC 5945 · No Item Name Available
Verified by PartsTable
NSN 5945-00-977-5850 — this item is cataloged by the U.S. Government under National Stock Number 5945-00-977-5850. Primary manufacturer part number: 42558.
Features
  • Relay,thermal — FSC 5945
  • Contact Maximum Current Rating in Amps: 0.6 AC
  • Contact Maximum Voltage Rating in Volts: 600.0 AC
  • Environmental Protection: DUSTPROOF
  • Mounting Facility Type and Quantity: 2 UNTHREADED HOLE(S)
  • Contact Arrangement: SINGLE POLE, SINGLE THROW, NORMALLY CLOSED
  • 1 verified cross-reference
  • Primary manufacturer: Cooper Industries Inc Cooper Distribution Equipment Div
Applications
  • Circuit control and protection
  • Equipment power management
  • Signal routing
General Description

The Relay,thermal, cataloged under National Stock Number 5945-00-977-5850, 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 Cooper Industries Inc Cooper Distribution Equipment Div. Government technical data includes 5 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 1 commercial cross-reference from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 3 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN5945-00-977-5850
Primary Part Number42558
Item NameRelay,thermal
FSC / FSG5945 / 59 — No Item Name Available
ManufacturerCooper Industries Inc Cooper Distribution Equipment Div
StatusACTIVE
Contact Maximum Current Rating in Amps0.6 AC
Contact Maximum Voltage Rating in Volts600.0 AC
Environmental ProtectionDUSTPROOF
Mounting Facility Type and Quantity2 UNTHREADED HOLE(S)
Contact ArrangementSINGLE POLE, SINGLE THROW, NORMALLY CLOSED
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 3
4920-00-838-6316 INTERCHANGEABLE
Matrix Module Assy
4810-00-953-500542558 INTERCHANGEABLE
Sleeve and Slide,directional Con
Woodward Hrt Inc
2990-01-254-626222186 INTERCHANGEABLE
Muffler,exhaust
Walker Mfg Co
Cross-Reference Index
Part NumberManufacturer
42558 Cooper Industries Inc Cooper Distribution Equipment Div (USA)
Related Parts
4920-00-838-6316INTERCHANGEABLE
MATRIX MODULE ASSY
4810-00-953-5005INTERCHANGEABLE
SLEEVE AND SLIDE,DIRECTIONAL CON
42558
2990-01-254-6262INTERCHANGEABLE
MUFFLER,EXHAUST
22186

Frequently Asked Questions

What is NSN 5945-00-977-5850?

NSN 5945-00-977-5850 is a Relay,thermal, manufactured by Cooper Industries Inc Cooper Distribution Equipment Div, classified under FSC 5945 (No Item Name Available). Status: active.

What are the part numbers for NSN 5945-00-977-5850?

NSN 5945-00-977-5850 has 1 cross-referenced part number: 42558 (Cooper Industries Inc Cooper Distribution Equipment Div).

What NSN replaces 5945-00-977-5850?

There are 3 known substitutes for 5945-00-977-5850: 4920-00-838-6316, 4810-00-953-5005, 2990-01-254-6262. Verify interchangeability with system specifications before substitution.

What are the specifications of 42558?

Key specifications for 42558: Contact Maximum Current Rating in Amps: 0.6 AC; Contact Maximum Voltage Rating in Volts: 600.0 AC; Environmental Protection: DUSTPROOF; Overall Length: 4.250 INCHES NOMINAL IN. 9 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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