NSN 5999-00-421-1861 · NIIN 004211861 · Part number 21-312
Eaton Corp Opns & Technical Center · FSC 5999 — Miscellaneous Electrical and Electronic Components · FSG 59 — Electrical and Electronic Equipment Components · CAGE 15605
Government record, cited
NSN 5999-00-421-1861 — this item is cataloged by the U.S. Government under National Stock Number 5999-00-421-1861. Manufacturer of record part number: 21-312.
Nearby stock numbers← 5999-00-421-1617
·
5999-00-421-1949 Delay Line →
Features
Contact Assembly,electrical — FSC 5999
Structural Design: NONSWITCHING
Government Agency Controlling Contact: USN
Contact Quantity: 2
Contact Item Name Assigned by Government Agency: CONTACT ASSY
Contact Identifying Number Assigned by Government Agency: PUB5487ITEM22 AND 21-312 AND 4690ALT1ITEM5 AND 4725ALT1ITEM5 AND 85986W1ITEM5 AND 87070W1ITEM5
6 manufacturer part numbers on file
Manufacturer of record: Eaton Corp Opns & Technical Center
Identification
NSN: 5999-00-421-1861
NIIN: 004211861
FSC: 5999 — Miscellaneous Electrical and Electronic Components
FSG: 59 — Electrical and Electronic Equipment Components
Primary part number: 21-312
Manufacturer: Eaton Corp Opns & Technical Center
General Description
The Contact Assembly,electrical, cataloged under National Stock Number 5999-00-421-1861, is classified within Federal Supply Class 5999 (Miscellaneous Electrical and Electronic Components) of the Electrical and Electronic Equipment Components group. The manufacturer of record is Eaton Corp Opns & Technical Center. Government technical data includes 5 specifications, cited from the U.S. Government catalog. The record lists 6 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 8 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active. Unit of issue: EA.
Technical Specifications
Parameter
Value
NSN
5999-00-421-1861
Primary Part Number
21-312
Item Name
Contact Assembly,electrical
FSC / FSG
5999 / 59 — Miscellaneous Electrical and Electronic Components
Manufacturer
Eaton Corp Opns & Technical Center
Status
ACTIVE
Structural Design
NONSWITCHING
Government Agency Controlling Contact
USN
Contact Quantity
2
Contact Item Name Assigned by Government Agency
CONTACT ASSY
Contact Identifying Number Assigned by Government Agency
PUB5487ITEM22 AND 21-312 AND 4690ALT1ITEM5 AND 4725ALT1ITEM5 AND 85986W1ITEM5 AND 87070W1ITEM5
Lifecycle & Compliance
Acquisition Status
ACTIVE
DEMIL Code
DEMIL A — No Demilitarization Required
Hazard
Possible hazard — SDS may be required (DLA HMIC P)
Shelf Life Code
0
Criticality Code
X
Unit of Issue
EA
Acquisition advice code
J
Weight
0.0100 lbs
Cube
0.0016 cu ft
⇄Related Items8
Each row states its source: a government interchangeability/replacement code, or a possible match on a shared part number.
6685-00-527-9325POSSIBLE MATCH
THERMOMETER,SELF-INDICATING
Possible match (shared part number)
4730-00-537-930421312POSSIBLE MATCH
EXPANSION JOINT,PIPE
Possible match (shared part number)Hyspan Precision Products, Inc.
3120-00-661-913521-312POSSIBLE MATCH
BEARING,SLEEVE
Possible match (shared part number)Dresser Industries Inc Leroi Div
2910-01-117-725221312POSSIBLE MATCH
SLEEVE,GOVERNOR THR
Possible match (shared part number)Stanadyne Corporation Dba Stanadyne Diesel Systems Div Diesel Systems
4730-01-348-058521312POSSIBLE MATCH
ELBOW,HOSE
Possible match (shared part number)National Oil Well Dba Iec Baylor
5998-01-371-480521312POSSIBLE MATCH
CIRCUIT CARD ASSEMBLY
Possible match (shared part number)Anritsu Instruments Company Div Mbu
2940-01-378-323421312POSSIBLE MATCH
INDICATOR,FILTER WARNING,VEHICUL
Possible match (shared part number)Quincy Compressor Division of Coltec Industries Inc Dba Quincy Compressor Div Quincy Compressor
4820-01-421-168921312-001POSSIBLE MATCH
VALVE,LINEAR,DIRECTIONAL CONTROL
Possible match (shared part number)Sargent Aerospace & Defense, Llc Dba Sargent Controls & Aerospace Div Sargent Controls & Aerospace
NSN 5999-00-421-1861 is a Contact Assembly,electrical, manufactured by Eaton Corp Opns & Technical Center, classified under FSC 5999, Miscellaneous Electrical and Electronic Components. Status: active.
What part numbers are listed for NSN 5999-00-421-1861?
NSN 5999-00-421-1861 has 6 manufacturer part numbers on file: PUB5487ITEM22 (Eaton Corp Opns & Technical Center), 4690ALT1ITEM5 (Eaton Corp Opns & Technical Center), 21-312 (Eaton Corp Opns & Technical Center), 4725ALT1ITEM5 (Eaton Corp Opns & Technical Center), 87070W1ITEM5 (Eaton Corp Opns & Technical Center) and 1 more.
What NSN replaces 5999-00-421-1861?
8 possible matches (shared part number, not a government interchangeability claim): 6685-00-527-9325, 4730-00-537-9304, 3120-00-661-9135. Verify interchangeability with system specifications before substitution.
What are the specifications of 21-312?
Key specifications for 21-312: Overall Height: 0.344 INCHES NOMINAL IN; Structural Design: NONSWITCHING; Government Agency Controlling Contact: USN; Overall Length: 0.106 INCHES NOMINAL IN. 5 specifications are documented in the U.S. Government catalog.
Is NSN 5999-00-421-1861 hazardous material?
Possible hazard — SDS may be required (DLA HMIC P). Hazard information on this page is shown exactly as it appears in the DLA record.
Sources
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.
✓ Data cited from the U.S. Government catalog; commercial cross-references from OEM and certified industry sources.