Micro Ball Bearings

High-Precision Micro Ball Bearings - Direct Supply from the Source (BLH Bearings Factory)

Looking for high-speed, low-noise miniature bearing solutions?
Contact the BLH engineering team today to request free samples and 3D drawings. (OEM/ODM services available for custom dimensions and materials.)

As precision medical instruments and intelligent microelectronic devices continue to evolve toward greater miniaturization and higher rotational speeds, the dimensional precision and operational stability of their core internal transmission components directly determine the service life of the entire system. BLH Bearings (Dongguan Good Power Bearing Co., Ltd.) specializes in the R&D and large-scale manufacturing of micro ball bearings with inner diameters ranging from 1mm to 50mm. As illustrated in our product imagery, our flagship micro bearings-such as the S681, 681X, and MR52 series-are smaller than a human fingertip, yet they integrate super-finished inner and outer rings, high-precision steel balls, and wave-shaped retainers.
As a primary supplier of micro ball bearings certified under the IATF 16949:2016 automotive quality management system, BLH Bearings utilizes imported ultra-clean stainless steel (AISI 440C / SUS304) and high-carbon chromium bearing steel (GCr15), strictly adhering to ISO 492 and ABEC-5/ABEC-7 tolerance standards. Whether meeting the demands of dental turbine handpieces operating at hundreds of thousands of revolutions per minute, or ensuring near-silent performance within the micro-modules of wearable smart devices, BLH's micro ball bearings provide stable, reliable, and low-friction support.

• Micron-level Raceway Super-finishing: Both the inner and outer raceways undergo multiple stages of super-finishing, keeping roundness deviation within 0.5μm. This significantly reduces frictional torque and temperature rise during high-speed operation.
• Specially Selected Corrosion-Resistant Steel: Designed for medical and humid operating environments, we primarily utilize S681-grade 440C martensitic stainless steel. Through vacuum quenching and cryogenic treatment, the material achieves a hardness of HRC 58–62, offering an optimal balance of high wear resistance and superior rust protection.
• 100% Full Inspection and Automotive-Grade Quality Control: Adhering to the IATF 16949 quality management system, every batch of micro bearings undergoes automated screening-including vibration (Z3/Z4 grade) and noise testing-before leaving the factory. This ensures smooth, silent operation once installed in the customer's end equipment.
• Flexible Delivery from the Source: Our modern production facility in Zhangmutou Town, Dongguan, features fully automated high-speed grinding machines and cleanroom assembly workshops. With over 500 standard miniature bearing models in stock, we support rapid delivery for small-batch trial production as well as stable, large-scale OEM supply.

To assist R&D and procurement engineers in making quick selections, the technical specifications for BLH bearings-which are regularly kept in stock-are provided below. (Note: Internal clearance and grease specifications can be adjusted to suit specific operating conditions.)

Please contact us if you would like to learn about additional models.

Dental handpieces represent the largest market segment for miniature bearings and demand the highest level of technical expertise. During dental procedures, these devices must withstand ultra-high rotational speeds-ranging from 300,000 to 450,000 RPM-while also enduring repeated exposure to high-temperature, high-pressure steam sterilization (autoclaving).
• BLH Recommended Solution: S681 / S681X stainless steel/ceramic hybrid ball bearings (featuring PEEK cages).
• Key Benefits: The 440C stainless steel rings provide effective resistance against corrosion from moisture and disinfecting agents. The ultra-low starting torque ensures highly responsive, instantaneous start-stop performance for the dental drill, which helps reduce hand fatigue for practitioners and significantly extends the clinical service life of the handpiece core mechanism.

Components such as smartwatch crowns, the internal micro-transmission mechanisms of fitness trackers, and the focusing modules of periscope-style smartphone cameras face extreme spatial constraints-often down to the millimeter-and are highly sensitive to operational noise.
• BLH Recommended Solution: ABEC-5 / ABEC-7 grade ultra-thin open-type or ZZ-shielded micro ball bearings.
• Addressing Key Challenges: These bearings provide smooth, consistent resistance (damping feel) within ultra-narrow, 1mm-scale spaces. Through Z4-grade noise-level screening and the use of high-quality, low-noise grease imported from Japan, they ensure a completely silent operation-free from any mechanical friction sounds-even when used in close proximity to the user's ear.

Applications such as optical scanning galvanometers, laser rangefinder rotating shafts, and the miniature articulating joints of medical endoscopes require bearings with exceptional rotational concentricity and dust resistance. Even the slightest radial runout or grease outgassing can cause optical path misalignment or lens contamination.
• BLH Recommended Solution: Miniature bearings with double-sided dust shields (ZZ type) or precision open-type bearings, utilizing low-volatility grease.
• Key Benefits: Radial runout is strictly controlled to within 2μm, ensuring precise positioning for lasers and optical lenses; the use of specialized, low-outgassing grease prevents the condensation of oil mist within optical cavities.

• Minimally Invasive Medical and Laboratory Equipment: Surgical power shavers, as well as laboratory-grade micro-peristaltic and syringe pumps-all requiring non-magnetic properties, resistance to chemical reagents, and long-term operational stability.
• Drones and Miniature Robots: Three-axis micro-motors for drone gimbals and joints for biomimetic robotic fingers-demanding lightweight construction and high resistance to impact loads.
• Micro-scale Power and Sensing: Miniature brushless coreless motors, micro-cooling fans for servers, internal components for high-end pressure-sensitive styluses, and precision optoelectronic encoders.

For overseas buyers in the medical device, consumer electronics, and precision industrial sectors, supply chain stability and compliance are of paramount importance. BLH Bearings (Dongguan Good Power Bearing Co., Ltd.) has established a robust production and management system aligned with international standards, with all certifications verifiable online through the respective official issuing bodies:

• IATF 16949:2016 Quality Management System Certification for the Automotive Industry
• Certification Body: URS (United Registrar of Systems), UK | Certificate No.: 86746/A/0001/SM/En
• Value to Customers: Our expertise encompasses the manufacturing of stainless steel bearings, high-temperature-resistant bearings, and custom non-standard bearings. We have integrated rigorous, automotive-grade "zero-defect" process controls-including SPC (Statistical Process Control) and PPAP (Production Part Approval Process)-into our miniature bearing production lines, ensuring consistent dimensional accuracy and an exceptionally low defect rate, even at a production scale of millions of units.

• ISO 9001:2015 International Quality Management System Certification
• Certification Body: URS (UK) - accredited by UKAS (United Kingdom Accreditation Service) and recognized under the IAF (International Accreditation Forum) Multilateral Recognition Arrangement | Certificate No.: 86746/AA/0001/SM/En
• Value to Customers: Having successfully passed annual international surveillance audits since 2018, we ensure full-process traceability-from spectral analysis of incoming raw materials and hardness monitoring during heat treatment to comprehensive vibration testing of finished products.

• ISO 14001:2015 Environmental Management System Certification
• Certification Body: Shenzhen Huantong Certification Center (CNAS-accredited and recognized under the IAF Multilateral Recognition Arrangement) | Certificate No.: 02422E32290905ROS
• Value to Clients: Ensures full compliance with EU RoHS and REACH environmental regulations; utilizes eco-friendly cleaning agents and non-hazardous production processes, helping end-brand clients in Europe, the U.S., and Japan successfully pass green supply chain audits.

If you require the original certificate, please contact us. Thank you.

Case 1: A German manufacturer and repair service provider for dental instruments (Model purchased: S681XZZ, hybrid ceramic version)
• Customer Pain Point: Previously used standard stainless steel bearings suffered from cage deformation and reduced rotational speed after 150 cycles of high-temperature, high-pressure (autoclave) sterilization, leading to a high rate of product returns for repair.
• BLH Solution: Leveraging an IATF 16949-compliant R&D process, BLH developed a customized solution featuring 440C steel rings with thickened inner races, imported PEEK cages, and silicon nitride ceramic balls. Additionally, the C3 internal clearance was adjusted to accommodate thermal expansion during high-speed operation.
• Results: Operational lifespan during in-device testing increased by approximately 40%, and the return-for-repair rate per batch dropped to below 0.8%. A long-term supply agreement has since been established for 50,000 units per quarter.

 Case 2: A developer of optical modules for consumer electronics based in California, USA (Purchased model: 681ZZ, customized for silent operation)
• Client Pain Point: The micro-adjustment knobs on their new AR smart glasses produced a faint "rustling" noise during rotation. Additionally, the outer diameter tolerance of the bearings had to be strictly maintained within a negative range to facilitate press-fitting.
• BLH Solution: Within five days, the BLH engineering team provided three sets of samples featuring varying internal clearances and grease viscosities for blind testing. The final selection combined a low-viscosity, silent-grade lubricant with ABEC-7 precision manufacturing.
• Outcome: The bearings successfully passed the client's rigorous acoustic laboratory testing-achieving noise levels below 20dB-and the company was subsequently approved as an official supplier.

Case 3: A Japanese manufacturer of miniature cooling fans and precision motors (Purchased model: MR52ZZ; supplied in bulk)
• Customer Pain Points: Miniature fans used in high-end laptops and communication modules require 24/7 continuous operation, demanding exceptionally high consistency and reliable delivery schedules for miniature ball bearings.
• BLH Solution: Implemented dedicated, fully automated production lines, incorporating in-line vibration testing to automatically reject any non-conforming units.
• Results: Achieved a batch consistency rate of over 99.6% for 12 consecutive months, helping the customer reduce their total procurement costs by approximately 18%.

Whether you are seeking high-precision samples for a new project or looking to optimize procurement costs within your existing supply chain, BLH Bearings (Dongguan Good Power Bearing Co., Ltd.) offers dedicated, one-on-one technical support:
1. Free Sample Testing: We provide up to 20 free samples for standard models (such as S681, 681ZZ, MR52ZZ, etc.) to help you quickly complete assembly verification.
2. Rapid Engineering Response: We supply comprehensive 2D/3D drawings (in STEP/IGES formats), along with technical reports covering service life and maximum rotational speed calculations.
3. Direct Factory Pricing: Eliminate intermediary markups; we also offer custom laser marking and a choice of neutral or branded packaging.

Q1: What is the smallest size of micro ball bearings you offer?
A1: Currently, the smallest inner diameter (ID) we mass-produce at the BLH factory is 1.0 mm (e.g., models 681 and S681, which have an outer diameter of 3.0 mm and a thickness of 1.0 mm). If you have specific requirements for non-standard micro bearings with an inner diameter of 0.6 mm or 0.8 mm, our R&D team can provide custom solutions, including mold development.

Q2: Should I choose open-type bearings or those with metal shields (ZZ) for high-speed dental handpieces (dental drills)?
A2: Both types are widely used in dental handpieces, depending on the lubrication and sealing design of the handpiece mechanism. If the handpiece features an integrated automatic oiling/cleaning system and an external labyrinth seal, open-type bearings are typically preferred to allow for proper lubricant circulation and heat dissipation. If the design utilizes long-life, maintenance-free grease, we recommend using the ZZ (double-sided metal shield) configuration to prevent water mist and debris-generated during dental procedures-from entering the raceways.

Q3: What are the performance differences between 440C stainless steel (S-series) and GCr15 bearing steel, and how should I choose between them?
A3: GCr15 bearing steel offers high hardness, superior load-bearing capacity, and a cost advantage; it is well-suited for applications in dry, clean environments, such as smartwatches, micro-fans, and standard brushless motors. 440C stainless steel (e.g., S681) provides excellent rust and corrosion resistance, along with greater dimensional stability at high temperatures. It is the preferred material for dental handpieces, minimally invasive medical devices, laboratory pump components, and equipment used in humid or outdoor environments.

Q4: As a professional supplier of miniature ball bearings, does BLH provide free samples?
A4: Yes, we do. For our standard, in-stock models-which include hundreds of options such as the S681, 681ZZ, 681XZZ, and MR52ZZ-we offer free samples for your assembly testing. You simply need to cover the international shipping costs (or provide your own DHL/FedEx collect account), and we can typically arrange shipment within 24 hours.

Q5: How do you ensure consistent noise levels and precision across every batch of miniature bearings during large-scale procurement?
A5: BLH Bearings operates in strict accordance with the IATF 16949:2016 and ISO 9001:2015 quality management systems, utilizing fully automated CNC grinding and super-finishing production lines. During assembly, components are cleaned and precisely lubricated within a Class 10,000 (ISO 7) cleanroom. Every finished bearing undergoes testing via an automated vibration-acceleration analyzer-screening for Z3/Z4-grade noise standards-before being packaged and placed into inventory, ensuring high consistency across all batches.

Q6: Do your products comply with environmental regulations in European and North American markets? Can you provide the relevant documentation?
A6: Yes, they are fully compliant. We are certified under the ISO 14001:2015 environmental management system (accredited by CNAS). All exported miniature bearings are manufactured using eco-friendly materials and processes. We can provide Material Test Reports (MTR), RoHS/REACH compliance declarations, and copies of our official system certificates for your records or factory audits.

Q7: What are the lead times for standard versus customized models?
A7: For standard, in-stock models, we can arrange shipment within 2–5 business days of order confirmation. For large-volume orders or OEM products requiring custom specifications-such as specific internal clearances, specialized lubricants, or non-standard dimensions-the production lead time is typically 15~25 business days.