PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

MIL-DTL-25988/2O-Ring

Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M · NSN 5331-00-351-6971 · FSC 5331 · O-Ring
Verified by PartsTable
NSN 5331-00-351-6971 — this item is cataloged by the U.S. Government under National Stock Number 5331-00-351-6971. Primary manufacturer part number: MIL-DTL-25988/2.
Features
  • O-Ring — FSC 5331
  • Elongation Percentage: 125 MAXIMUM
  • Material: RUBBER
  • Center Hole Diameter: 2.339 INCHES MINIMUM AND 2.379 INCHES MAXIMUM IN
  • Outside Diameter: 2.637 INCHES NOMINAL IN
  • Hardness Rating: 75.0 SHORE DUROMETER A NOMINAL
  • Cross-Sectional Height: 0.135 INCHES MINIMUM AND 0.143 INCHES MAXIMUM IN
  • 5 verified cross-references
Applications
  • Fluid containment and leak prevention
  • Pressure boundary maintenance
  • Environmental sealing
  • Applications requiring Rubber construction
General Description

The O-Ring, cataloged under National Stock Number 5331-00-351-6971, 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 5 commercial cross-references from 3 manufacturers, enabling identification through both NSN and commercial part number lookups. 9 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN5331-00-351-6971
Primary Part NumberMIL-DTL-25988/2
Item NameO-Ring
FSC / FSG5331 / 53 — O-Ring
ManufacturerMilitary Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
StatusCANCELLED
Elongation Percentage125 MAXIMUM
MaterialRUBBER
Center Hole Diameter2.339 INCHES MINIMUM AND 2.379 INCHES MAXIMUM IN
Outside Diameter2.637 INCHES NOMINAL IN
Hardness Rating75.0 SHORE DUROMETER A NOMINAL
Cross-Sectional Height0.135 INCHES MINIMUM AND 0.143 INCHES MAXIMUM IN
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 9
5330-00-153-104199-4601-501 INTERCHANGEABLE
Packing Special
Hamilton Sundstrand Corporation
5331-00-211-8040L1120 5-818 INTERCHANGEABLE
O-Ring
Parker-Hannifin Corp Div O-Ring Division
5331-00-401-4902 INTERCHANGEABLE
O-Ring
5331-00-421-9429 INTERCHANGEABLE
O-Ring
5331-01-007-8799 INTERCHANGEABLE
O-Ring
5331-01-030-18260.080IDX0.035W COMPOUND TH-1057 INTERCHANGEABLE
O-Ring
Stillman Seal Corporation Div Stillman Seal Corperation
5331-01-030-229582005512-025 INTERCHANGEABLE
O-Ring
Woodward Hrt Inc
5331-01-102-5597016-002460-903 INTERCHANGEABLE
O-Ring
Northrop Grumman Systems Corporation Dba Northrop Grumman Systems Corp Div Multiple
9320-01-202-4622 INTERCHANGEABLE
Rubber Sheet,solid
Cross-Reference Index
Part NumberManufacturer
MIL-DTL-25988/2 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
M25988/2-229 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
MIL-R-25988B Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
S9412-229 Honeywell International Inc. Dba Honeywell International Div Aerospace - Phoenix (USA)
5331PL0813745 Jednolity Indeks Materialowy - Uniform Material Index (POL)
Related Parts
5330-00-153-1041INTERCHANGEABLE
PACKING SPECIAL
99-4601-501
5331-00-211-8040INTERCHANGEABLE
O-RING
L1120 5-818
5331-00-401-4902INTERCHANGEABLE
O-RING
5331-00-421-9429INTERCHANGEABLE
O-RING
5331-01-007-8799INTERCHANGEABLE
O-RING
5331-01-030-1826INTERCHANGEABLE
O-RING
0.080IDX0.035W COMPOUND TH-1057
5331-01-030-2295INTERCHANGEABLE
O-RING
82005512-025
5331-01-102-5597INTERCHANGEABLE
O-RING
016-002460-903
9320-01-202-4622INTERCHANGEABLE
RUBBER SHEET,SOLID

Frequently Asked Questions

What is NSN 5331-00-351-6971?

NSN 5331-00-351-6971 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: cancelled.

What are the part numbers for NSN 5331-00-351-6971?

NSN 5331-00-351-6971 has 5 cross-referenced part numbers: MIL-DTL-25988/2 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), M25988/2-229 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), MIL-R-25988B (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), S9412-229 (Honeywell International Inc. Dba Honeywell International Div Aerospace - Phoenix), 5331PL0813745 (Jednolity Indeks Materialowy - Uniform Material Index).

What NSN replaces 5331-00-351-6971?

There are 9 known substitutes for 5331-00-351-6971: 5330-00-153-1041, 5331-00-211-8040, 5331-00-401-4902 and 6 more. Verify interchangeability with system specifications before substitution.

What are the specifications of MIL-DTL-25988/2?

Key specifications for MIL-DTL-25988/2: Elongation Percentage: 125 MAXIMUM; Material: RUBBER; Center Hole Diameter: 2.339 INCHES MINIMUM AND 2.379 INCHES MAXIMUM IN; Outside Diameter: 2.637 INCHES NOMINAL IN. 6 total characteristics are documented in the Federal Logistics Information System.

Is NSN 5331-00-351-6971 still in active supply?

NSN 5331-00-351-6971 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.
PartsTable Design LLC · partstable.com