PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

MILG21610O-Ring

Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M · NSN 5331-00-078-7889 · FSC 5331 · O-Ring
Verified by PartsTable
NSN 5331-00-078-7889 — this item is cataloged by the U.S. Government under National Stock Number 5331-00-078-7889. Primary manufacturer part number: MILG21610.
Features
  • O-Ring — FSC 5331
  • Center Hole Diameter: 9.454 INCHES MINIMUM AND 9.514 INCHES MAXIMUM IN
  • Cross-Sectional Height: 0.135 INCHES MINIMUM AND 0.143 INCHES MAXIMUM IN
  • Material: RUBBER BUTADIENE-ACRYLONITRILE CLASS NBR
  • 2 verified cross-references
  • Primary manufacturer: Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
Applications
  • Fluid containment and leak prevention
  • Pressure boundary maintenance
  • Environmental sealing
  • Applications requiring Rubber Butadiene-Acrylonitrile Class Nbr construction
General Description

The O-Ring, cataloged under National Stock Number 5331-00-078-7889, is classified within Federal Supply Class 5331 (O-Ring) of the Hardware and Abrasives group. The primary manufacturer of record is Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M. Government technical data includes 3 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. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN5331-00-078-7889
Primary Part NumberMILG21610
Item NameO-Ring
FSC / FSG5331 / 53 — O-Ring
ManufacturerMilitary Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
StatusACTIVE
Center Hole Diameter9.454 INCHES MINIMUM AND 9.514 INCHES MAXIMUM IN
Cross-Sectional Height0.135 INCHES MINIMUM AND 0.143 INCHES MAXIMUM IN
MaterialRUBBER BUTADIENE-ACRYLONITRILE CLASS NBR
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 12
5331-00-058-1409820-4-50001-79 INTERCHANGEABLE
O-Ring
DC Fabricators Inc
5331-00-058-1410820-4-80002-524 INTERCHANGEABLE
O-Ring
Siemens Energy, Inc.
5331-00-058-1411820-4-80002-525 INTERCHANGEABLE
O-Ring
Siemens Energy, Inc.
5331-00-078-7890AS568-216 INTERCHANGEABLE
O-Ring
Sae International Dba Sae International
5330-00-239-06852601-1479-7 INTERCHANGEABLE
Packing,preformed
Electric Boat Corporation Div General Dynamics Electric Boat
5330-00-595-6667 INTERCHANGEABLE
Packing,preformed
5331-00-892-194325176 INTERCHANGEABLE
O-Ring
Eaton Corporation Dba Eaton Inoac Div Eaton
5331-00-892-4222 INTERCHANGEABLE
O-Ring
9320-00-892-4724 INTERCHANGEABLE
Rubber Round Section
5331-00-892-5010820-4-80002-527 INTERCHANGEABLE
O-Ring
Siemens Energy, Inc.
Cross-Reference Index
Part NumberManufacturer
MILG21610 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
75G8R6012 Zf Industrieantriebe Witten Gmbh (DEU)
Related Parts
5331-00-058-1409INTERCHANGEABLE
O-RING
820-4-50001-79
5331-00-058-1410INTERCHANGEABLE
O-RING
820-4-80002-524
5331-00-058-1411INTERCHANGEABLE
O-RING
820-4-80002-525
5331-00-078-7890INTERCHANGEABLE
O-RING
AS568-216
5330-00-239-0685INTERCHANGEABLE
PACKING,PREFORMED
2601-1479-7
5330-00-595-6667INTERCHANGEABLE
PACKING,PREFORMED
5331-00-892-1943INTERCHANGEABLE
O-RING
25176
5331-00-892-4222INTERCHANGEABLE
O-RING
9320-00-892-4724INTERCHANGEABLE
RUBBER ROUND SECTION
5331-00-892-5010INTERCHANGEABLE
O-RING
820-4-80002-527
5331-01-062-4833INTERCHANGEABLE
O-RING
4678530-0015
5331-01-075-2064INTERCHANGEABLE
O-RING
203-4678530 ITEM 0014

Frequently Asked Questions

What is NSN 5331-00-078-7889?

NSN 5331-00-078-7889 is a O-Ring, manufactured by Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M, classified under FSC 5331 (O-Ring). Status: active.

What are the part numbers for NSN 5331-00-078-7889?

NSN 5331-00-078-7889 has 2 cross-referenced part numbers: MILG21610 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), 75G8R6012 (Zf Industrieantriebe Witten Gmbh).

What NSN replaces 5331-00-078-7889?

There are 12 known substitutes for 5331-00-078-7889: 5331-00-058-1409, 5331-00-058-1410, 5331-00-058-1411 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of MILG21610?

Key specifications for MILG21610: Center Hole Diameter: 9.454 INCHES MINIMUM AND 9.514 INCHES MAXIMUM IN; Cross-Sectional Height: 0.135 INCHES MINIMUM AND 0.143 INCHES MAXIMUM IN; Material: RUBBER BUTADIENE-ACRYLONITRILE CLASS NBR. 3 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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