PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

MS21231-4Bearing,plain,self-Aligning

Military Standards Promulgated by Military Departments Under Authority of Defense Standardization Manual 4120 3-M · NSN 3120-00-937-9186 · FSC 3120 · No Item Name Available
Verified by PartsTable
NSN 3120-00-937-9186 — this item is cataloged by the U.S. Government under National Stock Number 3120-00-937-9186. Primary manufacturer part number: MS21231-4.
Features
  • Bearing,plain,self-Aligning — FSC 3120
  • Bore Diameter: 0.2495 INCHES MINIMUM AND 0.2500 INCHES MAXIMUM IN
  • Hardness Rating: 55.0 ROCKWELL C MINIMUM INNER MEMBER
  • Style Designator: WITH INSERT AND/OR LINER
  • Material: PLASTIC POLYTETRAFLUOROETHYLENE OR GLASS RACE LINER
  • Material: STEEL COMP 440C INNER MEMBER
  • Outer Member Outside Diameter: 0.6245 INCHES MINIMUM AND 0.6250 INCHES MAXIMUM IN
  • Static Radial Load Rating: 9000 POUNDS LBS
Applications
  • Rotating machinery support and alignment
  • Shaft load distribution
  • Precision spindle assemblies
  • Applications requiring Plastic Polytetrafluoroethylene or Glass Race Liner construction
General Description

The Bearing,plain,self-Aligning, cataloged under National Stock Number 3120-00-937-9186, is classified within Federal Supply Class 3120 (No Item Name Available) of the Bearings group. The primary manufacturer of record is Military Standards Promulgated by Military Departments Under Authority of Defense Standardization Manual 4120 3-M. Government technical data includes 11 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. 1 verified substitute exists in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN3120-00-937-9186
Primary Part NumberMS21231-4
Item NameBearing,plain,self-Aligning
FSC / FSG3120 / 31 — No Item Name Available
ManufacturerMilitary Standards Promulgated by Military Departments Under Authority of Defense Standardization Manual 4120 3-M
StatusACTIVE
Bore Diameter0.2495 INCHES MINIMUM AND 0.2500 INCHES MAXIMUM IN
Hardness Rating55.0 ROCKWELL C MINIMUM INNER MEMBER
Style DesignatorWITH INSERT AND/OR LINER
MaterialPLASTIC POLYTETRAFLUOROETHYLENE OR GLASS RACE LINER
MaterialSTEEL COMP 440C INNER MEMBER
Outer Member Outside Diameter0.6245 INCHES MINIMUM AND 0.6250 INCHES MAXIMUM IN
Static Radial Load Rating9000 POUNDS LBS
Outer Member Width0.3220 INCHES MINIMUM AND 0.3320 INCHES MAXIMUM IN
MaterialSTEEL CORROSION RESISTING OUTER RACE MEMBER
Hardness Rating23.0 ROCKWELL C MINIMUM OUTER RACE MEMBER
Inner Member Width0.4350 INCHES MINIMUM IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 1
3120-01-015-6923MS14102-4 INTERCHANGEABLE
Bearing,plain,self-Aligning
Sae International Dba Sae International
Cross-Reference Index
Part NumberManufacturer
MS21231-4 Military Standards Promulgated by Military Departments Under Authority of Defense Standardization Manual 4120 3-M
Related Parts
3120-01-015-6923INTERCHANGEABLE
BEARING,PLAIN,SELF-ALIGNING
MS14102-4

Frequently Asked Questions

What is NSN 3120-00-937-9186?

NSN 3120-00-937-9186 is a Bearing,plain,self-Aligning, manufactured by Military Standards Promulgated by Military Departments Under Authority of Defense Standardization Manual 4120 3-M, classified under FSC 3120 (No Item Name Available). Status: active.

What are the part numbers for NSN 3120-00-937-9186?

NSN 3120-00-937-9186 has 1 cross-referenced part number: MS21231-4 (Military Standards Promulgated by Military Departments Under Authority of Defense Standardization Manual 4120 3-M).

What NSN replaces 3120-00-937-9186?

There is 1 known substitute for 3120-00-937-9186: 3120-01-015-6923. Verify interchangeability with system specifications before substitution.

What are the specifications of MS21231-4?

Key specifications for MS21231-4: Bore Diameter: 0.2495 INCHES MINIMUM AND 0.2500 INCHES MAXIMUM IN; Hardness Rating: 55.0 ROCKWELL C MINIMUM INNER MEMBER; Style Designator: WITH INSERT AND/OR LINER; Material: PLASTIC POLYTETRAFLUOROETHYLENE OR GLASS RACE LINER. 11 total characteristics are documented in the Federal Logistics Information System.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
PartsTable Design LLC · partstable.com