Frequently Asked Questions

HCH Bearing Group specializes in producing six core precision bearing series:

• Deep Groove Ball Bearings — The most versatile rolling bearing, suitable for electric motors, automotive, home appliances, and precision instruments
• Flexible / Thin-Section Bearings — Ultra-thin cross-section design, used in robot joints, harmonic reducers, aerospace
• Miniature / Micro Bearings — Starting from 1mm bore diameter, used in micro motors, dental handpieces, drones
• Four-Point Contact Bearings — Bidirectional axial load capacity, used in harmonic reducers, automotive EPS steering systems
• Tapered Roller Bearings — High combined load capacity, used in RV reducers, construction machinery, heavy-duty transmissions
• Crossed Roller Bearings — Multi-directional compound load capacity, rotational accuracy ≤0.005mm, used in robot joints, CNC rotary tables

Annual output exceeds 800 million units, covering a full size range from 1mm bore diameter to several meters outer diameter.

Bearing selection requires comprehensive consideration of the following factors:

• Load type and magnitude: Pure radial load — choose deep groove ball bearings; combined load — choose tapered roller or crossed roller bearings; bidirectional axial load — choose four-point contact bearings
• Space constraints: When installation space is tight, flexible/thin-section bearings or miniature bearings are recommended
• Accuracy requirements: For high-precision applications such as robot joints, P5/P4/P2 grade crossed roller bearings or flexible bearings are recommended
• Speed requirements: For high-speed applications (e.g., electric motors), deep groove ball bearings are recommended, capable of up to 30,000 RPM
• Operating environment: For high-temperature, corrosive, or other special environments, stainless steel materials or special lubrication solutions can be selected

We recommend contacting our technical team (james@hchbearing.com) and providing your specific operating parameters to receive a free selection proposal.

Both are widely used in robot harmonic reducers, but each has its own focus:

• Flexible Bearings (Thin-Section Bearings): Uniform cross-section ultra-thin design, using elastic deformation to achieve harmonic transmission, 30%-50% lighter, suitable for robot joints and aerospace equipment with strict weight and space requirements
• Crossed Roller Bearings: Cylindrical rollers arranged orthogonally, a single bearing simultaneously handles radial, axial, and overturning moment loads, rotational accuracy ≤0.005mm, higher rigidity, suitable for high-precision, high-load robot joints and CNC rotary tables

In simple terms: flexible bearings pursue lightweight design, while crossed roller bearings pursue high rigidity and high precision. The two may be used together within the same harmonic reducer.

Bearing accuracy grades correspond to international standards — the smaller the number, the higher the accuracy:

• P0 Grade (ABEC-1): Normal accuracy, suitable for general industrial applications
• P6 Grade (ABEC-3): Medium accuracy, used in electric motors, home appliances, etc.
• P5 Grade (ABEC-5): High accuracy, used in machine tool spindles, precision motors
• P4 Grade (ABEC-7): Ultra-precision, used in robot joints, CNC rotary tables, medical equipment
• P2 Grade (ABEC-9): Highest accuracy, used in precision measuring instruments, optical equipment

HCH has full production capability from P0 to P2 grades, and our CNAS-accredited laboratory can issue accuracy inspection reports.

HCH Bearing strictly implements international quality management system standards:

• IATF 16949: Automotive industry quality management system certification (automotive-grade products)
• ISO 9001: International quality management system certification
• CNAS-Accredited Laboratory: Testing laboratory accredited by the China National Accreditation Service for Conformity Assessment
• Zhejiang Province "SRDI" Enterprise: Government-recognized Specialized, Refined, Differential, Innovative enterprise qualification

Testing equipment includes world-class instruments such as Taylor Hobson roundness testers (UK), SPECTRO spectrometers (Germany), ZEISS metallurgical microscopes, and 30+ life testing machines.

HCH Bearing standard materials and special options:

• Standard Material: High-quality bearing steel GCr15 (high-carbon chromium bearing steel), offering excellent wear resistance and fatigue life
• Stainless Steel: 440C stainless steel, with superior corrosion resistance, suitable for food machinery, medical equipment, and humid environments
• Special Coatings: DLC (diamond-like carbon) coatings, chrome plating, and other surface treatment options available upon request

For special material or heat treatment requirements, please contact our technical team for customization.

Bearing service life depends on operating conditions (load, speed, lubrication, temperature, contamination, etc.). HCH ensures long service life through the following measures:

• Use of high-quality bearing steel (GCr15) and precision heat treatment processes
• 30+ life testing machines for full-batch reliability verification
• 300+ digital production lines ensuring product consistency
• Comprehensive lubrication solutions (grease lubrication and oil lubrication available)

Under standard operating conditions, HCH deep groove ball bearings have a design life of 20,000-50,000 hours. Specific calculations depend on application conditions. Contact our technical team for L10 life calculation support.

HCH Bearing has flexible production capabilities with adaptable MOQ:

• Standard Products: MOQ is typically 100-500 units, depending on the specific model
• Custom Products: Minimum batch size is evaluated based on technical requirements, generally starting from 1,000 units
• Sample Requests: Free samples are available for testing and validation

For specific MOQ inquiries, please contact our sales team: james@hchbearing.com | +86 574-6397-8888

HCH is known for rapid delivery, with standard inventory typically retained for only three days:

• Standard Products: Shipped within 3 days from stock; urgent orders processed within 24 hours
• Custom Products: Generally delivered in 2-4 weeks depending on technical requirements; expedited delivery can be shortened to 1-2 weeks
• Strategic Customers: Dedicated stock reservation mechanism for rapid response

Leveraging 300+ digital production lines and full supply chain in-house manufacturing capabilities, HCH can complete large-volume orders within a short timeframe.

To obtain an accurate quotation, please provide the following information:

• Bearing model number or drawing (for non-standard bearings)
• Required quantity (annual demand or single batch quantity)
• Accuracy grade requirement (P0/P6/P5/P4/P2)
• Material requirement (bearing steel / stainless steel)
• Sealing type (Open / ZZ metal shields / 2RS rubber seals)
• Special requirements (high temperature, high speed, low noise, etc.)

Send the above information to james@hchbearing.com and we will provide a detailed quotation within 1-2 business days.

HCH Bearing has a well-established global presence:

• Products exported to 70+ countries and regions
• 18 overseas direct sales companies established
• Domestic offices in Dongguan, Wuhan, Chongqing, and other locations
• Long-term partnerships with global leaders including Bosch, Siemens, Brose, Nidec, WEG, and more

12-hour domestic on-site response; overseas customers receive localized technical support from regional subsidiary companies.

Yes, HCH possesses strong customization capabilities:

• 100+ R&D team + CNAS-accredited laboratory providing custom development support
• Core grinding equipment independently developed and manufactured in-house, enabling rapid production line adjustment for non-standard bearings
• Full supply chain in-house production (from steel tube manufacturing to assembly), offering high customization flexibility
• Equipped with SolidWorks, CAD, and other professional design software, supporting collaborative design

Customization scope includes: non-standard dimensions, special materials, specialized coatings, custom lubrication, special sealing structures, and more.

HCH provides full-chain bearing solutions for the robotics industry:

• Harmonic Reducers: Flexible bearings, crossed roller bearings, four-point contact bearings
• RV Reducers: Tapered roller bearings
• Joint Modules: Flexible bearings, crossed roller bearings
• Servo Motors / Frameless Torque Motors: Deep groove ball bearings
• Dexterous Hands: Miniature / micro bearings (starting from 1mm bore diameter)

In May 2026, 12 dedicated crossed roller bearing production lines were officially commissioned, further strengthening supply capability in the robotics sector.

Yes, full-range product PDF technical manuals are available for free download on the Downloads page:

• Deep Groove Ball Bearing Technical Manual
• Flexible / Thin-Section Bearing Technical Manual
• Miniature and Micro Bearing Technical Manual
• Four-Point Contact Bearing Technical Manual
• Tapered Roller Bearing Technical Manual
• Crossed Roller Bearing Technical Manual
• Grease Specification Sheet

For printed copies or customized technical solutions, please contact james@hchbearing.com.