PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

21-256Contact,electrical

Eaton Corp Opns & Technical Center · NSN 5999-00-368-1054 · FSC 5999 · No Item Name Available
Verified by PartsTable
NSN 5999-00-368-1054 — this item is cataloged by the U.S. Government under National Stock Number 5999-00-368-1054. Primary manufacturer part number: 21-256.
Features
  • Contact,electrical — FSC 5999
  • Nominal Thread Size: 0.138 INCHES IN
  • Surface Treatment: CADMIUM BODY AND CONTACT
  • Material: COPPER ALLOY BODY AND CONTACT
  • Style Designator: IRREGULAR SHAPE
  • Thread Series Designator: UNIFIED NATIONAL COARSE (UNC)
  • Thread Quantity Per Inch: 32
  • Mounting Facility Quantity: 1
Applications
  • Applications requiring Copper Alloy Body and Contact construction
General Description

The Contact,electrical, cataloged under National Stock Number 5999-00-368-1054, is classified within Federal Supply Class 5999 (No Item Name Available) of the Electrical and Electronic Equipment Components group. The primary manufacturer of record is Eaton Corp Opns & Technical Center. Government technical data includes 20 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 2 commercial cross-references from 2 manufacturers, enabling identification through both NSN and commercial part number lookups. 5 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled. Unit of issue: EA.

Technical Specifications
ParameterValue
NSN5999-00-368-1054
Primary Part Number21-256
Item NameContact,electrical
FSC / FSG5999 / 59 — No Item Name Available
ManufacturerEaton Corp Opns & Technical Center
StatusCANCELLED
Nominal Thread Size0.138 INCHES IN
Surface TreatmentCADMIUM BODY AND CONTACT
MaterialCOPPER ALLOY BODY AND CONTACT
Style DesignatorIRREGULAR SHAPE
Thread Series DesignatorUNIFIED NATIONAL COARSE (UNC)
Thread Quantity Per Inch32
Mounting Facility Quantity1
Thread DirectionRIGHT-HAND
Thread Class2B
Mounting MethodTHREADED HOLE(S)
Nominal Thread Size0.138 INCHES IN
Surface TreatmentCADMIUM BODY AND CONTACT
MaterialCOPPER ALLOY BODY AND CONTACT
Style DesignatorIRREGULAR SHAPE
Thread Series DesignatorUNIFIED NATIONAL COARSE (UNC)
Thread Quantity Per Inch32
Mounting Facility Quantity1
Thread DirectionRIGHT-HAND
Thread Class2B
Mounting MethodTHREADED HOLE(S)
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Shelf Life Code0
Criticality CodeQ
Unit of IssueEA
SMR CodeJ
Weight0.0200 lbs
Cube0.0010 cu ft
Verified Substitutes 5
5110-00-194-5982 INTERCHANGEABLE
Reamer,hand
3120-00-448-347221-256 INTERCHANGEABLE
Bearing Half,sleeve
Dresser Industries Inc Leroi Div
5977-00-799-81362-1257 INTERCHANGEABLE
Brush,electrical Contact
Kearfott Corporation Div Guidance and Navigation Division
3010-01-297-556926511 INTERCHANGEABLE
Coupling,shaft,flexible
Rexnord Industries, Llc Div Couplings Division
6105-01-524-399421256 INTERCHANGEABLE
Motor,direct Current
Silver King Refrigeration Inc.
Cross-Reference Index
Part NumberManufacturer
21-256 PRIMARY Eaton Corp Opns & Technical Center (USA)
21-256 Drs Naval Power Systems Inc Dba Drs Power & Control Technologies Inc (USA)
Related Parts
5110-00-194-5982INTERCHANGEABLE
REAMER,HAND
3120-00-448-3472INTERCHANGEABLE
BEARING HALF,SLEEVE
21-256
5977-00-799-8136INTERCHANGEABLE
BRUSH,ELECTRICAL CONTACT
2-1257
3010-01-297-5569INTERCHANGEABLE
COUPLING,SHAFT,FLEXIBLE
26511
6105-01-524-3994INTERCHANGEABLE
MOTOR,DIRECT CURRENT
21256

Frequently Asked Questions

What is NSN 5999-00-368-1054?

NSN 5999-00-368-1054 is a Contact,electrical, manufactured by Eaton Corp Opns & Technical Center, classified under FSC 5999 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 5999-00-368-1054?

NSN 5999-00-368-1054 has 2 cross-referenced part numbers: 21-256 (Eaton Corp Opns & Technical Center), 21-256 (Drs Naval Power Systems Inc Dba Drs Power & Control Technologies Inc).

What NSN replaces 5999-00-368-1054?

There are 5 known substitutes for 5999-00-368-1054: 5110-00-194-5982, 3120-00-448-3472, 5977-00-799-8136 and 2 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 21-256?

Key specifications for 21-256: Nominal Thread Size: 0.138 INCHES IN; Surface Treatment: CADMIUM BODY AND CONTACT; Material: COPPER ALLOY BODY AND CONTACT; Style Designator: IRREGULAR SHAPE. 28 total characteristics are documented in the Federal Logistics Information System.

Is NSN 5999-00-368-1054 still in active supply?

NSN 5999-00-368-1054 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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