Rolling motion

Replacement bearings and seals: what to identify first

Bearings support motion; seals control leakage and contamination. Their part numbers, dimensions and service requirements must be checked separately. A shared measurement alone does not establish interchangeability.

Evidence boundary. Exact interchange rows should be published only when a manufacturer or authoritative catalog establishes them. A dimensional match alone is not proof of application compatibility.

Identify the correct replacementPart-number and service checks

For a bearingRecord the full bearing designation and suffix, bore, outside diameter, width, bearing arrangement and any mounting or clearance requirements. Verify the required load, speed, lubrication and protection with the manufacturer source.

For a shaft or oil sealIdentify the marked seal code, shaft diameter, housing bore, installed width, lip design and elastomer. Confirm the fluid, temperature, shaft condition and installation direction for the actual application.

For a mechanical sealDocument the pump and seal assembly, rotating and stationary faces, secondary seals and operating fluid. A face or spring that looks similar is not evidence of an acceptable service replacement.

Before orderingCompare the exact manufacturer part or documented interchange, including the suffix and duty limits. If the code is missing or the service is unclear, ask the OEM or a qualified supplier to verify the match.

Decode a bearing designation →Screen bearings by dimensions →Look up Timken metric oil seals →Identify mechanical-seal components →

Items covered01 · 16 component types

Ball bearings
Roller bearings
Needle bearings
Thrust bearings
Spherical bearings
Pillow block bearings
Flange bearings
Cartridge bearings
Mounted bearing units
Mechanical seals
Oil seals
Rotary shaft seals
O-rings
Gaskets
Wear sleeves
Labyrinth seals

What to capture02

Original designation and manufacturerRecord this before searching for a substitute.

Bore, outside diameter, width, and seal dimensionsRecord this before searching for a substitute.

Bearing or seal type and constructionRecord this before searching for a substitute.

Seal, shield, clearance, material, and cage suffixesRecord this before searching for a substitute.

Housing, shaft, fluid, temperature, and environmentRecord this before searching for a substitute.

What must match03

Boundary dimensions and toleranceConfirm it against the original equipment, duty, and source documentation.

Radial and axial load or sealing dutyConfirm it against the original equipment, duty, and source documentation.

Speed and lubricationConfirm it against the original equipment, duty, and source documentation.

Material, temperature, contamination, and fluid compatibilityConfirm it against the original equipment, duty, and source documentation.

Housing and shaft fitConfirm it against the original equipment, duty, and source documentation.

Common searches04

What bearing replaces this number?

How do I identify a bearing by dimensions?

What seal replaces this part number?

What does a bearing or seal suffix mean?

Authoritative starting points05

SKF rolling bearingshttps://www.skf.com/group/products/rolling-bearings Schaeffler industrial solutionshttps://www.schaeffler.us/us/products-and-solutions/industrial/

Manufacturer-backed spherical-roller lookup400 live NSK records

NSK spherical roller bearing lookup

Browse exact live NSK designations with boundary dimensions, basic load ratings, thermal speed ratings, limiting speeds, and direct manufacturer product links.

Browse 400 NSK spherical roller bearings →

Manufacturer-backed spherical-roller lookup400 live Timken records

Timken brass-cage spherical roller bearing lookup

Browse exact live Timken part numbers with bore, OD, static and dynamic radial load ratings, thermal reference speeds, and direct manufacturer item links.

Browse 400 Timken spherical roller bearings →

Manufacturer-backed tapered-roller lookup400 live JTEKT/Koyo records

Koyo metric and inch tapered roller bearing lookup

Browse exact live JTEKT/Koyo tapered-roller designations balanced across metric and inch families with dimensions, load ratings, fatigue limits, limiting speeds, technical-calculation links, and CAD.

Browse 400 Koyo tapered roller bearings →

Manufacturer-backed matched-pair lookup400 live JTEKT/Koyo DB pairs

Koyo back-to-back matched-pair angular contact bearing lookup

Browse exact live DB pair designations with dimensions, load ratings, fatigue limits, grease limiting speeds, and manufacturer calculation/CAD links.

Browse 400 Koyo DB angular contact pairs →

Manufacturer-backed tapered-roller lookup400 live NTN sets

NTN Inch and J Series tapered roller bearing set lookup

Browse exact live NTN cone/cup set identities with inch/mm dimensions, minimum corner radius, static and dynamic load ratings, and direct manufacturer item links.

Browse 400 NTN tapered roller sets →

Manufacturer-backed cylindrical-roller lookup400 live NSK records

NSK single-row cylindrical roller bearing lookup

Browse exact live NSK designations with boundary dimensions, basic load ratings, thermal speed ratings, limiting speeds, and direct manufacturer product links.

Browse 400 NSK cylindrical roller bearings →

Manufacturer-backed shielded/sealed lookup400 live JTEKT/Koyo records

Koyo shielded and sealed deep groove ball bearing lookup

Browse exact live JTEKT/Koyo designations with seal/shield classification, boundary dimensions, basic load ratings, fatigue limits, and manufacturer tools.

Browse 400 Koyo deep groove bearings →

Manufacturer-backed deep-groove lookup400 live NSK records

NSK single-row deep groove ball bearing lookup

Browse exact live NSK designations with boundary dimensions, basic load ratings, limiting speeds, and direct manufacturer product links.

Browse 400 NSK deep groove bearings →

Manufacturer-backed deep-groove lookup400 live Timken records

Timken deep groove ball bearing lookup

Browse exact live Timken 6000/6200/6300/6400-series records with dimensions, sealing/features, material, lubrication, radial load ratings, speed limits, and direct manufacturer links.

Browse 400 Timken deep groove bearings →

Manufacturer-backed radial-bearing lookup400 live NTN records

NTN single-row radial ball bearing lookup

Browse exact live NTN item numbers with bore, outside diameter, width, corner radius, static/dynamic load ratings, and direct manufacturer item links.

Browse 400 NTN radial ball bearings →

Manufacturer-backed needle-bearing lookup350 live NTN records

NTN drawn-cup needle roller bearing lookup

Browse current NTN item numbers with Fw, outer diameter, width, static/dynamic load ratings, and direct manufacturer item links.

Browse 350 NTN drawn-cup needle bearings →

Manufacturer-backed mounted bearing lookup500 Dodge part records

Dodge mounted ball bearing part-number lookup

Browse exact Dodge six-digit part numbers with manufacturer nomenclature, shaft-size context, mounting style, and source-row provenance.

Browse 500 Dodge mounted ball bearings →

Manufacturer-backed metric oil seal lookup350 live Timken records

Timken metric oil seal part-number lookup

Browse current Timken metric oil-seal part numbers with seal type, shaft size, housing bore, overall width, material, and direct manufacturer item links.

Browse 350 Timken metric oil seals →

Manufacturer-backed angular-contact bearing lookup350 SKF exact designations

SKF angular contact ball bearing designation lookup

Browse exact SKF single-row, double-row, and four-point-contact designations with dimensions, load ratings, speed ratings, mass, and source-row evidence.

Browse 350 SKF angular contact bearings →

Manufacturer-backed deep-groove bearing lookup350 SKF exact designations

SKF single-row deep groove ball bearing designation lookup

Browse exact SKF designations with bore, outside diameter, width, load ratings, fatigue limit, speed ratings, mass, and source-row evidence.

Browse 350 SKF deep groove ball bearings →

Manufacturer-backed bearing lookup350 Timken part records

Timken single-row metric cylindrical roller bearing lookup

Browse exact Timken part numbers with bore, outside diameter, width, load ratings, thermal speed ratings, mounting data, weight, and July 2025 catalog source pages.

Browse 350 Timken cylindrical roller bearings →

Related lookup guides2 workflows

bearing replacement by dimensions