SMR52ZZ Stainless Steel Miniature Ball Bearing (2mm x 5mm x 2.5mm)

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Product Overview

The SMR52ZZ stainless steel miniature ball bearing is a precision deep groove ball bearing with exact dimensions of 2mm inner diameter, 5mm outer diameter, and 2.5mm width. It is manufactured from high-grade AISI 440C martensitic stainless steel, specifically designed for compact, high-precision, and demanding applications where exceptional corrosion resistance and stable rotation performance are required. Compared with standard chrome steel bearings (such as MR52ZZ), this full stainless steel version provides significantly better resistance to moisture, high humidity, saltwater spray, and light chemical exposure. This makes the SMR52ZZ the absolute industry standard for environments where rust prevention, chemical stability, and extended machinery service life are critical. The bearing is equipped with double metal shields (ZZ type) to effectively retain internal high-speed lubrication while reducing contamination from dust, debris, and environmental particles.

Key Features

■ Premium AISI 440C Stainless Steel: Maximum rust prevention with high material hardness (HRC 58-60).

■ Ultra-Compact Design: Tailored specifically for micro-mechanisms and high-precision equipment.

■ Low Startup Torque: Delivers smooth, stable, and low-friction rotation performance under demanding speeds.

■ Double Metal Shield (ZZ) Protection: Retains factory grease and blocks foreign particle ingress.

■ High-Speed Reliability: Engineered for light load, high-speed micro rotation systems.

■ Full OEM Support: Custom clearances, lubrication options, and private label packaging available.

Technical Specifications

Chrome Steel vs Stainless Steel (Quick Reference)

Chrome Steel Bearings (MR52ZZ): Generally used in completely dry, enclosed, and high-load environments, offering maximum hardness and high cost efficiency. However, they will rust rapidly if exposed to moisture.

Stainless Steel Bearings (SMR52ZZ): Highly recommended for environments with moisture, humidity, water splash, or severe corrosion risk, where rust prevention and operational safety are the primary requirements.

Typical Applications

■ Fishing Reel Systems: Perfect for premium baitcasting and spinning fishing reels, specifically on spool shafts, handle assemblies, and line roller systems operating in aggressive saltwater marine environments.

■ Medical and Laboratory Equipment: Suitable for small rotating components, diagnostic tools, surgical instruments, and medical devices requiring strict sanitation or exposure to cleaning chemicals.

■ Micro Motors and RC Devices: Extensively used in high-end micro brushless motors, racing drones, RC quadcopters, and RC cars that frequently operate outdoors in damp grass, mud, or snow.

■ Precision Mechanical Systems: Applied in anemometers, wind speed sensors, miniature gearboxes, and optical instruments requiring stable, low-torque rotation in extremely limited space.

Compatible OEM Replacement Models

Material Advantage

The refined martensitic structure of our 440C stainless steel forms a passive chromium oxide protective layer. This micro-layer prevents chemical oxidation and eliminates the risk of premature bearing failure caused by rust, surface pitting, or moisture degradation. It ensures that your equipment maintains consistent operational accuracy even when routine maintenance or relubrication is difficult.

Why Choose EKB Bearings

■ Strict Quality Control: Ultrasonic cleaning and 100% automated optical inspections for assembly reliability.

■ Stable Factory Direct Supply: Reliable production capacity tailored for OEM schedules and wholesale buyers.

■ Engineering Support: Professional guidance for bearing material selection, internal clearance adjustment, and grease matching.

■ Flexible Sourcing Solutions: Capabilities to handle both standardized bulk supply and customized component requirements.

■ Export-Oriented Logistics: Industrial-grade anti-rust packaging with complete international customs documentation support.

Need Help Choosing the Right Bearing?

Not sure whether stainless steel or chrome steel is the most cost-effective choice for your project? Please provide our technical team with: 1. Exact dimensions; 2. Operating environment (moisture, temperature, chemicals); 3. Rotational speed and load conditions. Our engineering desk will analyze your working conditions and recommend the optimal solution.

Request a Quote

Looking for a reliable factory supplier of SMR52ZZ stainless steel miniature ball bearings? Contact EKB today for:

■ Free Product Samples for Engineering Testing

■ Tiered OEM Bulk Wholesale Pricing

■ Technical Data Sheets and CAD Drawings

■ Long-Term Stable Contract Supply Agreements

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