PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

T121O-Ring

Unertl John Optical Co Inc · NSN 5331-01-459-6758 · FSC 5331 · O-Ring
Verified by PartsTable
NSN 5331-01-459-6758 — this item is cataloged by the U.S. Government under National Stock Number 5331-01-459-6758. Primary manufacturer part number: T121.
Features
  • O-Ring — FSC 5331
  • Cross-Sectional Height: 0.070 INCHES NOMINAL IN
  • Color: BLACK
  • Material: RUBBER
  • Center Hole Diameter: 1.062 INCHES NOMINAL IN
  • 1 verified cross-reference
  • Primary manufacturer: Unertl John Optical Co Inc
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 5331-01-459-6758, is classified within Federal Supply Class 5331 (O-Ring) of the Hardware and Abrasives group. The primary manufacturer of record is Unertl John Optical Co Inc. Government technical data includes 4 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 1 commercial cross-reference from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 9 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN5331-01-459-6758
Primary Part NumberT121
Item NameO-Ring
FSC / FSG5331 / 53 — O-Ring
ManufacturerUnertl John Optical Co Inc
StatusACTIVE
Cross-Sectional Height0.070 INCHES NOMINAL IN
ColorBLACK
MaterialRUBBER
Center Hole Diameter1.062 INCHES NOMINAL IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 9
3110-00-100-548659200-59412 INTERCHANGEABLE
Bearing,roller,tapered
The Timken Corporation
5120-00-111-1254T12-1 INTERCHANGEABLE
Installing Tool,rin
Woodward Hrt Inc
5330-00-351-4132SCB61809 INTERCHANGEABLE
Gasket
Us Army Communications & Electronics Materiel Readiness Command Logistics Engineering Dir
5136-00-528-22991552 INTERCHANGEABLE
Tap,thread Cutting
Stanley Tools Div of Stanley Works
5220-00-545-9266T121 INTERCHANGEABLE
Handle,gage,checkin
Eaton Aerospace Llc Dba Sterer Engineering Div Valve & Actuator
3439-01-103-0244 INTERCHANGEABLE
Tip,electric Soldering Iron
3040-01-238-4010 INTERCHANGEABLE
Lever,manual Control
3110-01-491-8977T121 INTERCHANGEABLE
Bearing,roller,thrust
The Timken Corporation
5180-01-502-8951 INTERCHANGEABLE
Tool Kit,general Mechanic's
Cross-Reference Index
Part NumberManufacturer
T121 PRIMARY Unertl John Optical Co Inc (USA)
Related Parts
3110-00-100-5486INTERCHANGEABLE
BEARING,ROLLER,TAPERED
59200-59412
5120-00-111-1254INTERCHANGEABLE
INSTALLING TOOL,RIN
T12-1
5330-00-351-4132INTERCHANGEABLE
GASKET
SCB61809
5136-00-528-2299INTERCHANGEABLE
TAP,THREAD CUTTING
1552
5220-00-545-9266INTERCHANGEABLE
HANDLE,GAGE,CHECKIN
T121
3439-01-103-0244INTERCHANGEABLE
TIP,ELECTRIC SOLDERING IRON
3040-01-238-4010INTERCHANGEABLE
LEVER,MANUAL CONTROL
3110-01-491-8977INTERCHANGEABLE
BEARING,ROLLER,THRUST
T121
5180-01-502-8951INTERCHANGEABLE
TOOL KIT,GENERAL MECHANIC'S

Frequently Asked Questions

What is NSN 5331-01-459-6758?

NSN 5331-01-459-6758 is a O-Ring, manufactured by Unertl John Optical Co Inc, classified under FSC 5331 (O-Ring). Status: active.

What are the part numbers for NSN 5331-01-459-6758?

NSN 5331-01-459-6758 has 1 cross-referenced part number: T121 (Unertl John Optical Co Inc).

What NSN replaces 5331-01-459-6758?

There are 9 known substitutes for 5331-01-459-6758: 3110-00-100-5486, 5120-00-111-1254, 5330-00-351-4132 and 6 more. Verify interchangeability with system specifications before substitution.

What are the specifications of T121?

Key specifications for T121: Cross-Sectional Height: 0.070 INCHES NOMINAL IN; Color: BLACK; Material: RUBBER; Center Hole Diameter: 1.062 INCHES NOMINAL IN. 5 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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