CORROSION-RESISTANT BEARING SELECTION
Stainless steel bearings are selected when corrosion resistance, moisture, cleaning conditions or environmental exposure make conventional bearing steel less suitable.
Material grade, closure, lubricant, load and speed must be reviewed together; stainless steel is corrosion resistant, not completely rust-proof.
Stainless deep groove bearingSize checking
Compare 50 stainless model references by series, bore, outside diameter and published closure availability. Confirm the final suffix before ordering.
50 models
Confirm the final material, load and permissible speed| Model | Series / Family | Bore dmm | Outer Dmm | Width B Openmm | Width B Closed*mm | Closure | Material | RFQ |
|---|---|---|---|---|---|---|---|---|
| S68/0.6 | 68 Series | 0.6 | 2.5 | 1 | — | Open | Stainless Steel | RFQ |
| S681 | 68 Series | 1 | 3 | 1 | — | Open | Stainless Steel | RFQ |
| SMR31 | MR Series | 1 | 3 | 1.5 | — | Open | Stainless Steel | RFQ |
| S691 | 69 Series | 1 | 4 | 1.6 | — | Open | Stainless Steel | RFQ |
| SMR41X | MR Series | 1.2 | 4 | 1.8 | 2.5 | Open / ZZ | Stainless Steel | RFQ |
| S681X | 68 Series | 1.5 | 4 | 1.2 | 2 | Open / ZZ | Stainless Steel | RFQ |
| S691X | 69 Series | 1.5 | 5 | 2 | 2.6 | Open / ZZ | Stainless Steel | RFQ |
| S601X | 60 Series | 1.5 | 6 | 2.5 | 3 | Open / ZZ | Stainless Steel | RFQ |
| S672 | 67 Series | 2 | 4 | 1.2 | 2 | Open / ZZ | Stainless Steel | RFQ |
| S682 | 68 Series | 2 | 5 | 1.5 | 2.3 | Open / ZZ | Stainless Steel | RFQ |
| SMR52 | MR Series | 2 | 5 | 2 | 2.5 | Open / ZZ | Stainless Steel | RFQ |
| S692 | 69 Series | 2 | 6 | 2.3 | 3 | Open / ZZ | Stainless Steel | RFQ |
| SMR62 | MR Series | 2 | 6 | 2.5 | 2.5 | Open / ZZ | Stainless Steel | RFQ |
| SMR72 | MR Series | 2 | 7 | 2.5 | 3 | Open / ZZ | Stainless Steel | RFQ |
| S602 | 60 Series | 2 | 7 | 2.8 | 3.5 | Open / ZZ | Stainless Steel | RFQ |
| S682X | 68 Series | 2.5 | 6 | 1.8 | 2.6 | Open / ZZ | Stainless Steel | RFQ |
| S692X | 69 Series | 2.5 | 7 | 2.5 | 3.5 | Open / ZZ | Stainless Steel | RFQ |
| SMR82X | MR Series | 2.5 | 8 | 2.5 | — | Open | Stainless Steel | RFQ |
| S602X | 60 Series | 2.5 | 8 | 2.8 | 4 | Open / ZZ | Stainless Steel | RFQ |
| SMR63 | MR Series | 3 | 6 | 2 | 2.5 | Open / ZZ | Stainless Steel | RFQ |
| S683 | 68 Series | 3 | 7 | 2 | 3 | Open / ZZ / 2RS | Stainless Steel | RFQ |
| SMR83 | MR Series | 3 | 8 | 2.5 | 3 | Open / ZZ | Stainless Steel | RFQ |
| S693 | 69 Series | 3 | 8 | 3 | 4 | Open / ZZ / 2RS | Stainless Steel | RFQ |
| SMR93 | MR Series | 3 | 9 | 2.5 | 4 | Open / ZZ | Stainless Steel | RFQ |
| S603 | 60 Series | 3 | 9 | 3 | 5 | Open / ZZ | Stainless Steel | RFQ |
Showing 1–25 of 50 models
* Closed width is the published boundary width for the listed ZZ or 2RS variant. Where both closures are listed, no ZZ-to-2RS width difference was found in the referenced catalogues for these models. Load and permissible speed still require confirmation for the actual grade, closure and lubricant.
Engineering definition
Engineers normally move from bearing steel to stainless steel because the operating environment changes the failure risk. Humidity, condensation, direct water, cleaning chemicals and cleanliness controls can make corrosion or lubricant condition more important than the maximum catalogue load rating.
Humidity, condensation, water, washdown and cleaning chemicals can make corrosion or lubricant condition more important than the dry-service catalogue rating.
Raceways, balls, cage, closures and lubricant can use different materials. The stainless grade on one component does not define the complete bearing.
Stainless steel is not rust-proof. Salt, reactive chemicals, temperature, storage and damaged or contaminated surfaces can still lead to corrosion.
Material selection
These grades describe component roles, not three interchangeable complete-bearing options. Raceway duty usually requires a hardened martensitic stainless steel.
The typical stainless bearing material in this group. Hardened 440C-type steels are used for raceways, rings and balls where rolling-contact duty requires hardness and wear resistance together with better corrosion resistance than conventional bearing steel.
Used in some bearing components, retainers and application-specific constructions. Its role depends on heat treatment and design; it should not be presented as the standard ring material for every stainless bearing.
Used where corrosion resistance and formability are important, commonly for shields, cages, retainers or other non-raceway components. Its lower hardness means it is not normally a direct substitute for hardened 440C-type raceways in higher-load or higher-speed duty.
Do not assume that 304, 420 and 440C are freely selectable for every model. Confirm the complete component stack and the rating for the finished bearing construction.
Material system comparison
Stainless steel solves an environmental requirement; it is not automatically the higher-performance choice in every machine.
| Selection point | Stainless Steel Bearings | Bearing Steel Bearings |
|---|---|---|
| Corrosion resistance | Improved for moisture and corrosion-sensitive environments; still grade- and condition-dependent. | Limited; intended for dry service with suitable lubricant and storage protection. |
| Hardness / wear | Depends strongly on grade and heat treatment. 440C-type grades are chosen when raceway hardness matters. | High hardness and established wear performance for general bearing duty. |
| Load capability | Must be confirmed for the actual stainless grade and bearing design; do not transfer bearing-steel ratings automatically. | Often the practical reference for demanding loads in dry industrial service. |
| Speed | Permissible speed may be lower than an equivalent bearing-steel configuration. Confirm the actual stainless grade, heat treatment, closure, cage, lubricant, fit and temperature. | Dry-service bearing-steel designs usually have established load, fatigue and speed data for general industrial duty. |
| Environment | Humidity, condensation, cleaning, water splash or corrosion-sensitive equipment. | Dry, protected industrial environments. |
| Cost | Normally higher because material, processing and configuration controls differ. | Usually more economical for standard dry-service requirements. |
| Typical application | Clean equipment, instruments, humid machinery and corrosion-sensitive assemblies. | Motors, gearboxes and general machinery in controlled dry conditions. |
Environment review
Material grade is one input. Exposure path, closure, lubricant and storage determine whether the complete bearing system remains protected.
Repeated wet/dry cycles can attack rings, balls and interfaces even without continuous water contact.
Direct water, splash and washdown are different duties. Closure, grease and cleaning method must be reviewed together.
Dry particles are primarily a contamination and sealing problem; stainless steel alone does not keep them out of the raceway.
Reactive gases and corrosive fumes are a material-compatibility problem. Standard 440C-type stainless may not be sufficient.
Saltwater, chlorides and aggressive chemicals can cause localized attack and require a separate material review.
Grease condition, packaging, fingerprints, temperature cycles and surface damage can change corrosion performance before or during service.
Contamination and grease control
Choose the closure after defining contamination, grease retention, running resistance, moisture and chemical compatibility.
Lowest closure drag and direct lubricant access, but little protection from moisture or contamination at the raceway.
Helps retain grease and exclude larger particles with lower running resistance than a contacting rubber seal.
Provides stronger moisture and contamination protection with improved grease retention, but adds seal drag and can reduce permissible speed.
Closure selection does not determine the stainless grade. Confirm the ring, ball, cage, shield or seal materials for the selected suffix and application.
Exposure reasons by application
Each application still requires confirmation of actual moisture, cleaning, chemical, load, speed and lubricant conditions.
Miniature size, precision rotation and repeated cleaning can make moisture and corrosion control important. Lubricant and material compatibility remain device-specific.
Small size, low torque and controlled runout matter. Stainless construction is relevant when humidity, condensation or external exposure adds corrosion risk.
Washdown, humidity and cleaning can justify corrosion-resistant construction. Food-safe status still depends on the complete bearing, seal and lubricant specification.
Condensation, rain splash and storage humidity can attack raceways and interfaces. Direct exposure still requires closure and lubricant review.
Stainless construction is relevant only when a compact motor faces moisture, condensation or corrosive exposure. Speed, noise and grease life still govern selection.
Compact sensors, scanners and small outdoor devices may combine precision rotation with condensation or weather exposure. Load, speed and sealing remain application-specific.
Selection workflow
Complete the environmental definition before choosing a grade or closure.
Start with the model or d × D × B envelope and any installation constraints.
Separate protected indoor service from outdoor, clean-equipment, washdown or process exposure.
Record humidity, condensation, direct water and salt rather than using ‘wet’ as a single condition.
Record cleaning agent, concentration, pH, dwell time, rinse quality and frequency.
Match ring, ball, cage and closure materials to corrosion exposure and mechanical duty.
Set contamination control, grease retention and acceptable running resistance.
Do not copy bearing-steel ratings. Check the actual stainless grade, heat treatment, closure, cage, lubricant, fit and temperature.
Match grease or oil to temperature, cleaning exposure, life and cleanliness requirements.
Define clearance, runout, vibration and acoustic requirements before sample approval.
Engineering & OEM support
Provide the bearing envelope and the real corrosion or cleaning exposure so the material, closure and lubricant can be reviewed together.
Send RequirementsTranslate moisture, chemicals, temperature, load, speed and cleanliness into a material and closure brief.
Confirm grade, closure, lubricant, clearance, precision and noise requirements for the selected model.
Check the approved dimensions and agreed inspection items before repeat production.
Align annual quantity, packaging, storage and delivery requirements with the confirmed specification.
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Related products
Use the family page that matches the governing geometry or environment. Stainless Steel Bearings remains a Products-level family, not a child of Miniature Ball Bearings.
Technical answers
They resist corrosion better than conventional bearing steel, but they are not completely rust-proof. Grade, salt, chemicals, moisture, temperature, lubricant, storage and surface condition all affect the result.
Provide the model or dimensions, operating environment, stainless grade preference and closure. LUMI can review the configuration against the application before quotation.