1 Complete Model & Code Explanation

Model: W 623-2RS1

Code Definition

W: Stainless steel series symbol

623: Light series small-size deep groove ball bearing

2RS1: Double-sided contact rubber seal with optimized lip structure

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

Important reminder: W 623-2RS1 is a sealed miniature stainless steel bearing capable of radial loads and moderate bidirectional axial loads. The 2RS1 contact rubber seal provides reliable dust and mild humidity protection, it only resists incidental splash moisture and must not be continuously immersed or exposed to liquid water and strong corrosive media for long periods. Grease is pre-sealed from factory with no relubrication structure, suitable for medium-to-long term maintenance-free continuous or intermittent operation. Friction from sealing lip reduces the achievable limiting speed compared with open and metal shield variants.

Basic Parameters

Bore d: 3 mm

Outer diameter D: 10 mm

Width B: 4 mm

Bearing type: Single-row deep groove ball bearing

Number of rows: Single row

Bore form: Straight cylindrical bore

Seal arrangement: Double-sided rubber seal

Seal type: 2RS1 contact rubber sealing ring

Oil groove: Without oil groove

Outer ring locating feature: No locating groove or shoulder

Cage: Stamped stainless steel cage

Radial internal clearance: CN standard clearance

Material: Stainless steel

Surface coating: Uncoated

Pre-installed lubricant: Long-life grease (factory pre-filled)

Relubrication capability: Not available

Duplex arrangement: Not supported, single unit operation only

Basic dynamic load rating: 0.148 kN

Basic static load rating: 0.056 kN

Reference speed: 135 000 r/min

Limiting speed: 68 000 r/min

Net weight: 0.00022 kg

Indicative carbon footprint: 0.00062 kg CO₂e

eClass code: 23-05-08-01

UNSPSC code: 31171504

Series Suffix Comparison

W 623: Open type without seal, highest limiting speed, no environmental protection

W 623-Z: Single metal shield, only blocks dry dust

W 623-2Z: Double metal shields, dust protection without moisture resistance

W 623-2RS1: Double contact rubber seal (this model), dust & moisture resistance, limited speed

623-2RS1: Bearing steel variant with identical dimensions, similar load capacity, no rust resistance

2 Structure & Operating Characteristics

Japan NMT W 623-2RS1 belongs to W623 stainless steel miniature deep groove ball bearing series, developed for small rotary mechanisms exposed to both dust and mild humidity. Fully manufactured from stainless steel, it delivers consistent anti-corrosion performance over bearing steel alternatives, ideal for precision equipment that is difficult to disassemble regularly and prone to internal moisture contact.

Equipped with integrated stamped stainless steel cage. Compact structure ensures stable dynamic balance and reduced vibration at high speed. Two ends are fitted with improved lip-type 2RS1 contact rubber seals. The sealing lips closely fit bearing rings, blocking moisture and fine dust from entering raceways and offering basic splash resistance superior to metal shields. Nevertheless, continuous contact of seal lips creates frictional loss, resulting in lower maximum permissible rotational speed than Z-type shielded bearings. Standard CN radial clearance matches common tolerance specifications of small rotary shafts.

The moderate contact area between rolling elements and raceways allows the bearing to carry primary radial loads together with certain bidirectional axial loads. The sealing system only copes with splash moisture and cannot support underwater operation; full housing sealing is still required for long-term high-humidity or submerged working conditions. Long-life grease specially formulated for sealed miniature bearings is pre-filled at factory for immediate assembly and commissioning.

3 Core Performance Advantages

1. Standard small dimension: 3mm bore × 10mm OD × 4mm width, widely compatible with various compact precision transmission mechanisms.

2. Stainless steel construction: Inherent rust resistance suitable for slightly humid equipment interiors.

3. Double 2RS1 contact rubber seals: Balanced dust protection and basic resistance against moisture and splashing liquid.

4. Stamped stainless steel cage: Moderate weight, stable rotation and good resistance to minor shocks.

5. CN standard radial clearance: High universality and convenience for standardized mechanical design.

6. Factory pre-filled long-life grease: Eliminates on-site lubricant filling and streamlines assembly workflow.

7. Bidirectional axial load capacity: Better axial bearing capacity compared with ultra-thin miniature bearings.

4 Typical Application Fields

4.1 Portable Precision Medical Instruments

Transmission assemblies of handheld diagnostic equipment, rotary shafts of compact rehabilitation devices, motion units for minimally invasive auxiliary instruments.

4.2 Small Precision Drive Motors

Micro DC motors, built-in drive motors for portable devices, miniature servo fine-tuning spindles.

4.3 Optical Inspection Instrument Components

Portable optical detection equipment, lens adjustment assemblies, rotary parts of precision image sensors.

4.4 Smart Consumer Devices & Automation Components

Transmission structures of wearable equipment, miniature automated actuators, small laboratory test fixtures.

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

Assembly should be completed on clean workbenches to avoid hard particles scratching rubber sealing lips. Never strike inner or outer rings directly. Use dedicated tooling for uniform press fitting to prevent lip flaring damage and raceway tilt leading to rolling element failure. Strictly control interference between shaft and housing. Excessive interference reduces internal clearance and causes temperature rise together with premature seal aging.

5.2 Selection Guidance

Fully enclosed dust-free space, maximum rotational speed priority → W 623 open type;

Only dry dust exists and high speed is required → W 623-Z / W 623-2Z shielded models;

Exposed to dust, humidity and occasional liquid splashes requiring sealing protection → W 623-2RS1 (this model);

Dry indoor environment without anti-rust demand, load capacity prioritized → 623-2RS1 bearing steel version.

5.3 Lubrication Instruction

Sufficient long-life grease is pre-sealed inside the bearing. Extra lubrication is unnecessary under standard operating conditions. No built-in oil supply channel supports on-site re-greasing; designed for medium and long-term maintenance-free machinery. Continuous high-temperature operation is not recommended, which accelerates rubber seal aging and grease carbonization.

5.4 Environmental Application Notes

2RS1 contact rubber seals provide basic dust and humidity resistance, not suitable for continuous submersion, long-term salt spray exposure or contact with strong chemical solvents. Stainless steel delivers only fundamental corrosion resistance. Full machine sealing is advised for persistent high-humidity working environments to prevent continuous moisture penetration towards raceways.

6 Daily Maintenance & Fault Troubleshooting

Carry out low-speed running-in after assembly. Gradually increase speed to rated value only after confirming no abnormal noise or temperature rise. Common faults of sealed bearings include increased rotation torque, growing noise and external grease leakage.

Frequent failure causes: sealing lip scratch during assembly allowing contaminant ingress, seal degradation and grease depletion caused by prolonged overheating, insufficient clearance from improper fit tolerances, sustained excessive axial load. Damaged sealing lips cannot be repaired; complete bearing replacement is recommended once faults occur.