1 Complete Model & Code Explanation

Model：W 635-2RS1

Code Definition

W：Stainless steel series with basic rust prevention and mild corrosion resistance

635：Basic dimension specification of miniature deep groove ball bearing

2RS1：Double-side contact rubber seal, sealing lip contacts inner ring surface for superior sealing performance

Structure：Closed structure with built-in contact rubber seals on both ends

Supply form：Single independent bearing, no factory duplex grinding, DB/DF duplex arrangement not supported

Important reminder: W 635-2RS1 is stainless steel miniature sealed bearing. It delivers better rust resistance than bearing steel bearings with slightly lower load capacity. 2RS1 is contact-type rubber seal with excellent protection against dust, mist and splash water, outperforming non-contact 2Z shields. Continuous contact between seal lip and inner ring creates friction torque, so the maximum allowable speed is lower than same-size 2Z shielded bearings. Rubber seals cannot be dismantled; solvent cleaning and on-site re-lubrication are prohibited. Avoid long-term exposure to strong solvents and high-temperature grease to prevent rubber aging and deformation.

Basic Parameters

Bore d：5 mm

Outer diameter D：19 mm

Width B：6 mm

Bearing type：Single-row deep groove ball bearing

Number of rows：Single row

Bore form：Straight cylindrical bore

Seal arrangement：2RS1, double-side contact rubber seal

Cage：Stamped stainless steel cage

Material：Stainless steel

Surface coating：Uncoated

Pre-installed lubricant：General long-service grease

Relubrication capability：On-site re-greasing unavailable

Radial internal clearance：Normal clearance class

Duplex arrangement：Not supported, single unit operation only

Basic dynamic load rating：0.091 kN

Basic static load rating：0.036 kN

Reference speed：56 000 r/min

Limiting speed：39 000 r/min

Net weight：0.00031 kg

Indicative carbon footprint：0.00062 kg CO₂e

eClass code：23-05-08-01

UNSPSC code：31171504

Series Suffix Comparison

635-2RS1：Bearing steel, double contact rubber seal, standard grease

W 635：Open type stainless steel bearing without seal

W 635-2Z：Stainless steel double steel shield, high speed, basic protection

W 635-2RS1：Stainless steel double 2RS1 contact rubber seal (this model)

W 635-2RS1/VT378：Stainless steel 2RS1 seal, pre-filled VT378 food-contact grease

2 Structure & Operating Characteristics

Japan NMT W 635-2RS1 adopts standard 635 dimension platform, fully manufactured from stainless steel and equipped with double-side 2RS1 contact rubber seals, designed for humid, dusty environments with minor liquid splash. Stainless steel matrix effectively resists condensed moisture and fresh water mist to reduce rust risk. Contact rubber sealing lip closely fits the side of inner ring raceway to form a physical barrier blocking dust, mist and limited splash liquid from entering the bearing.

Friction from sealing lip brings higher rotating torque compared with steel shield variants and reduces limiting speed, so it is not suitable for continuous ultra-high-speed operation. Matched with standard radial clearance for assembly under normal temperature. Long-term high temperature accelerates aging and failure of rubber seals. Stamped stainless steel cage features corrosion resistance for light rotary components exposed to intermittent moisture. The bearing mainly bears radial loads and withstands moderate bidirectional axial loads. Long-term overspeed operation is prohibited.

3 Core Performance Advantages

1. Integrated W-series stainless steel construction achieves superior rust resistance over bearing steel bearings, suitable for humid and condensation-prone environments.

2. Double-side 2RS1 contact rubber seals provide effective protection against dust, mist and light splash water, sealing level far better than 2Z steel shields.

3. Standard 635 overall dimension enables direct interchangeability for equipment modification and spare part replacement.

4. Stable sealing structure with factory pre-filled grease supports long-term maintenance-free operation under normal working conditions.

5. Compact size with larger outer diameter, offering higher load capacity compared with 625 series miniature bearings.

6. Symmetrical sealing structure on both ends without installation orientation limitation, compatible with automatic production line assembly.

4 Typical Application Fields

4.1 Water Treatment & Humidification Equipment

Rotary shafts of small pure water equipment, transmission rollers inside humidifiers, light-duty rotary assemblies of water purification valves.

4.2 Light-Duty Food & Packaging Machinery

Non-high-temperature food conveyor guide rollers, idlers for wet stations on packaging lines, auxiliary transmission mechanisms for beverage equipment.

4.3 Laboratory Instruments

Humid physical & chemical test devices, rotary gimbals matched with water baths, miniature rotary shafts for environmental testing instruments.

4.4 Outdoor & Corrosion-Resistant Devices

Light outdoor automation components, inspection instruments under humid conditions, simple aquatic conveyor rollers.

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

Maintain clean assembly area to prevent hard particles entering the bearing. Press force shall only act on end faces of bearing rings. Knocking or squeezing rubber seals is strictly forbidden to avoid lip damage and seal failure. Stainless steel has relatively low hardness; prevent surface impact which may create corrosion initiation points. Symmetrical seal structure requires no specific installation direction.

5.2 Selection Guidance

Dry ultra-high speed, only coarse dust blocking → W 635-2Z

Humid, dusty, with mist & light splash, enhanced sealing priority → W 635-2RS1 (this model)

Humid environment with food hygiene requirements → W 635-2RS1/VT378

Continuous high temperature, strong chemical solvent environment → Special sealed bearing solution required

5.3 Lubrication Instruction

Pre-filled with general long-service grease at factory for maintenance-free operation under standard conditions. 2RS1 rubber seal forms enclosed internal structure. Forcible seal dismantling, solvent immersion cleaning and arbitrary addition of other grease types are strictly prohibited. Long-term high temperature and continuous liquid immersion accelerate grease deterioration and rubber hardening & cracking, drastically shortening bearing service life.

5.4 Environmental Application Notes

2RS1 contact seal can resist water mist and intermittent light splash, incapable of enduring prolonged liquid immersion or high-pressure water flushing. Stainless steel provides basic rust resistance but is not fully rust-proof; pitting corrosion occurs under long-term exposure to salt water or strong corrosive media. Prevent rubber seals from contacting aromatic solvents and strong acid/alkaline cleaners to avoid swelling and hardening failure.

6 Daily Maintenance & Fault Troubleshooting

Perform low-speed running-in after assembly, confirm no abnormal noise and temperature rise before gradually increasing to rated working speed. Common faults: steadily rising rotation resistance, abnormal running noise, grease leakage from aged seals, rust spots on outer ring surface.

Typical failure causes: moisture penetration due to worn sealing lip; rubber hardening and grease failure induced by persistent high temperature; seal damage caused by assembly extrusion; continuous operation exceeding limiting speed. Once seal rupture or rolling element rust & jamming occurs, the bearing cannot be repaired and replacement is recommended.