PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

M25988/1-381O-Ring

Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M · NSN 5331-00-118-4156 · FSC 5331 · O-Ring
Verified by PartsTable
NSN 5331-00-118-4156 — this item is cataloged by the U.S. Government under National Stock Number 5331-00-118-4156. Primary manufacturer part number: M25988/1-381.
Features
  • O-Ring — FSC 5331
  • Material: RUBBER FLUOROSILICONE CLASS FQ
  • Center Hole Diameter: 11.910 INCHES MINIMUM AND 12.040 INCHES MAXIMUM IN
  • Cross-Sectional Height: 0.205 INCHES MINIMUM AND 0.215 INCHES MAXIMUM IN
  • Elongation Percentage: 125 MAXIMUM
  • Hardness Rating: 70.0 SHORE DUROMETER A NOMINAL
  • Outside Diameter: 12.395 INCHES NOMINAL IN
  • 3 verified cross-references
Applications
  • Fluid containment and leak prevention
  • Pressure boundary maintenance
  • Environmental sealing
  • Applications requiring Rubber Fluorosilicone Class Fq construction
General Description

The O-Ring, cataloged under National Stock Number 5331-00-118-4156, 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 6 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 3 commercial cross-references from 2 manufacturers, enabling identification through both NSN and commercial part number lookups. 2 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN5331-00-118-4156
Primary Part NumberM25988/1-381
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
MaterialRUBBER FLUOROSILICONE CLASS FQ
Center Hole Diameter11.910 INCHES MINIMUM AND 12.040 INCHES MAXIMUM IN
Cross-Sectional Height0.205 INCHES MINIMUM AND 0.215 INCHES MAXIMUM IN
Elongation Percentage125 MAXIMUM
Hardness Rating70.0 SHORE DUROMETER A NOMINAL
Outside Diameter12.395 INCHES NOMINAL IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 2
5330-00-221-414468667 INTERCHANGEABLE
Gasket
Briggs and Stratton Corp
3020-01-066-7498AK6 34 INTERCHANGEABLE
Pulley,groove
TB Woods's Corporation
Cross-Reference Index
Part NumberManufacturer
M25988/1-381 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
MIL-DTL-25988/1 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
68-667 Goodrich Corporation Div Collins Aerospace, Landing Systems (wheels & Brakes) (USA)
Related Parts
5330-00-221-4144INTERCHANGEABLE
GASKET
68667
3020-01-066-7498INTERCHANGEABLE
PULLEY,GROOVE
AK6 34

Frequently Asked Questions

What is NSN 5331-00-118-4156?

NSN 5331-00-118-4156 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 5331-00-118-4156?

NSN 5331-00-118-4156 has 3 cross-referenced part numbers: M25988/1-381 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), MIL-DTL-25988/1 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), 68-667 (Goodrich Corporation Div Collins Aerospace, Landing Systems (wheels & Brakes)).

What NSN replaces 5331-00-118-4156?

There are 2 known substitutes for 5331-00-118-4156: 5330-00-221-4144, 3020-01-066-7498. Verify interchangeability with system specifications before substitution.

What are the specifications of M25988/1-381?

Key specifications for M25988/1-381: Material: RUBBER FLUOROSILICONE CLASS FQ; Center Hole Diameter: 11.910 INCHES MINIMUM AND 12.040 INCHES MAXIMUM IN; Cross-Sectional Height: 0.205 INCHES MINIMUM AND 0.215 INCHES MAXIMUM IN; Elongation Percentage: 125 MAXIMUM. 6 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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