PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

31481O-Ring

L3harris Technologies, Inc. Div Space and Airborne Systems · NSN 5331-00-165-1978 · FSC 5331 · O-Ring
Verified by PartsTable
NSN 5331-00-165-1978 — this item is cataloged by the U.S. Government under National Stock Number 5331-00-165-1978. Primary manufacturer part number: 31481.
Features
  • O-Ring — FSC 5331
  • Material: RUBBER FLUOROCARBON CLASS FPM
  • Outside Diameter: 1.934 INCHES MINIMUM AND 1.978 INCHES MAXIMUM IN
  • Hardness Rating: 75.0 SHORE DUROMETER A NOMINAL
  • Cross-Sectional Height: 0.114 INCHES MINIMUM AND 0.122 INCHES MAXIMUM IN
  • Center Hole Diameter: 1.706 INCHES MINIMUM AND 1.734 INCHES MAXIMUM IN
  • Elongation Percentage: 125 MAXIMUM
  • 49 verified cross-references
Applications
  • Fluid containment and leak prevention
  • Pressure boundary maintenance
  • Environmental sealing
  • Applications requiring Rubber Fluorocarbon Class Fpm construction
General Description

The O-Ring, cataloged under National Stock Number 5331-00-165-1978, is classified within Federal Supply Class 5331 (O-Ring) of the Hardware and Abrasives group. The primary manufacturer of record is L3harris Technologies, Inc. Div Space and Airborne Systems. Government technical data includes 6 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 49 commercial cross-references from 27 manufacturers, enabling identification through both NSN and commercial part number lookups. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN5331-00-165-1978
Primary Part Number31481
Item NameO-Ring
FSC / FSG5331 / 53 — O-Ring
ManufacturerL3harris Technologies, Inc. Div Space and Airborne Systems
StatusCANCELLED
MaterialRUBBER FLUOROCARBON CLASS FPM
Outside Diameter1.934 INCHES MINIMUM AND 1.978 INCHES MAXIMUM IN
Hardness Rating75.0 SHORE DUROMETER A NOMINAL
Cross-Sectional Height0.114 INCHES MINIMUM AND 0.122 INCHES MAXIMUM IN
Center Hole Diameter1.706 INCHES MINIMUM AND 1.734 INCHES MAXIMUM IN
Elongation Percentage125 MAXIMUM
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 12
5331-00-172-7189 INTERCHANGEABLE
O-Ring
2530-00-217-9490D65186 AND R52998 INTERCHANGEABLE
Cylinder Assembly,hydraulic Brak
Cnh Industrial America Llc Dba Cnh America
5331-00-456-2532E0540 3-924 INTERCHANGEABLE
O-Ring
Parker-Hannifin Corp Div O-Ring Division
5331-00-580-6330AS568-924 INTERCHANGEABLE
O-Ring
Sae International Dba Sae International
5340-00-624-363831-481 INTERCHANGEABLE
Seat,helical Compression Spring
Dresser Industries Inc Leroi Div
6640-00-774-121431481 INTERCHANGEABLE
Oven,laboratory
Precision Scientific Petroleum Instruments Co
5331-00-781-6958 INTERCHANGEABLE
O-Ring
5331-00-819-51113684372C1 INTERCHANGEABLE
O-Ring
Nd Defense Llc
5331-01-019-3775 INTERCHANGEABLE
O-Ring
5331-01-037-0799 INTERCHANGEABLE
O-Ring
Cross-Reference Index
Part NumberManufacturer
AS3208-24 Fincantieri S.p.a. Div Direzione Navi Militari (ITA)
3-24 V747-75 Parker-Hannifin Corp Div O-Ring Division (USA)
2306990 REV J IT NO 168 Rolls-Royce Corporation (USA)
5331PL0687369 Jednolity Indeks Materialowy - Uniform Material Index (POL)
3-924 V747-75 Parker Hannifin Gmbh O-Ring Division (DEU)
AS3208-24 Society of Automotive Engineers Inc (USA)
3-924 V747-75 Parker-Hannifin Corporation Dba Pneutronics Div Composite Sealing Systems Division (USA)
AMS7276 Sae International Dba Sae International (USA)
516-6818073 ITEM F-1B Naval Sea Systems Command (USA)
6375B Siemens Energy, Inc. Dba Dresser-Rand (USA)
M83248-1-1-924 Zf Industrieantriebe Witten Gmbh (DEU)
SAE-AMS7276 Sae International Dba Sae International (USA)
5331PL1813311 Jednolity Indeks Materialowy - Uniform Material Index (POL)
AS3208-24 Ge Avio Srl (ITA)
B-24SR2702-75 Stillman Seal Corporation Div Stillman Seal Corperation (USA)
MS9387-24 Military Standards Promulgated by Military Departments Under Authority of Defense Standardization Manual 4120 3-M
NAS1595-24 National Aerospace Standards Committee Aerospace Industries Association of America Inc Not for Rfq or Solicitation Use (USA)
M83248/1-924 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
6375B Curtiss-Wright Electro-Mechanical Corp Dba Steam & Air Solutions Div Curtiss-Wright Steam and Air Solutions (USA)
31481 PRIMARY L3harris Technologies, Inc. Div Space and Airborne Systems (USA)
Related Parts
5331-00-172-7189INTERCHANGEABLE
O-RING
2530-00-217-9490INTERCHANGEABLE
CYLINDER ASSEMBLY,HYDRAULIC BRAK
D65186 AND R52998
5331-00-456-2532INTERCHANGEABLE
O-RING
E0540 3-924
5331-00-580-6330INTERCHANGEABLE
O-RING
AS568-924
5340-00-624-3638INTERCHANGEABLE
SEAT,HELICAL COMPRESSION SPRING
31-481
6640-00-774-1214INTERCHANGEABLE
OVEN,LABORATORY
31481
5331-00-781-6958INTERCHANGEABLE
O-RING
5331-00-819-5111INTERCHANGEABLE
O-RING
3684372C1
5331-01-019-3775INTERCHANGEABLE
O-RING
5331-01-037-0799INTERCHANGEABLE
O-RING
5331-01-038-3074INTERCHANGEABLE
O-RING
3-924N552-90
5310-01-150-5014INTERCHANGEABLE
WASHER,FLAT
31481

Frequently Asked Questions

What is NSN 5331-00-165-1978?

NSN 5331-00-165-1978 is a O-Ring, manufactured by L3harris Technologies, Inc. Div Space and Airborne Systems, classified under FSC 5331 (O-Ring). Status: cancelled.

What are the part numbers for NSN 5331-00-165-1978?

NSN 5331-00-165-1978 has 49 cross-referenced part numbers: AS3208-24 (Fincantieri S.p.a. Div Direzione Navi Militari), 3-24 V747-75 (Parker-Hannifin Corp Div O-Ring Division), 2306990 REV J IT NO 168 (Rolls-Royce Corporation), 5331PL0687369 (Jednolity Indeks Materialowy - Uniform Material Index), 3-924 V747-75 (Parker Hannifin Gmbh O-Ring Division) and 44 more.

What NSN replaces 5331-00-165-1978?

There are 12 known substitutes for 5331-00-165-1978: 5331-00-172-7189, 2530-00-217-9490, 5331-00-456-2532 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 31481?

Key specifications for 31481: Material: RUBBER FLUOROCARBON CLASS FPM; Outside Diameter: 1.934 INCHES MINIMUM AND 1.978 INCHES MAXIMUM IN; Hardness Rating: 75.0 SHORE DUROMETER A NOMINAL; Cross-Sectional Height: 0.114 INCHES MINIMUM AND 0.122 INCHES MAXIMUM IN. 6 total characteristics are documented in the Federal Logistics Information System.

Is NSN 5331-00-165-1978 still in active supply?

NSN 5331-00-165-1978 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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