How to Vet a Chinese Bearing Manufacturer


China is home to the largest manufacturing base in the world. As a bearing company that has produced award-winning products in China for more than 20 years, we have witness other companies struggle to find the right partner.

What are some of the indicators that a Chinese manufacturer can consistently produce a great product for you?

Anyone can produce impressive samples

The manufacturing environment uses a range of skills, materials and procedures – as well as business ethics. Do not to be swayed simply by the samples. After all, a manufacturer can produce a batch of 1,000 units and pull 15 that meet requirements.

Too often, buyers are lulled into a relationship with a sample that meets all of their specifications and testing only to receive substandard

products on future orders. It is important to know how bearing production and quality will be maintained on all orders.

Audit the manufacturer

Fly to China and visit three to five bearing factories. Doing so will give you a comparative overview of the factory’s capabilities while building a relationship with key members of the manufacturer’s team.

Audits need to be setup a month in advance and should be confirmed one week from your arrival. A factory representative will meet you at the airport and take you to the facility, as well as accompany you throughout the audit.

A formal audit includes a detailed inspection of four factory sectors:

  • System – an independent examination of the entire quality assurance process to determine if the system is complete, well maintained, continuously developed and implemented effectively.
  • Process – a check to see if all processes are identified and controlled. The most important aspect of process is to see if the stability and capability (Cpk and Ppk) of each process can meet the target.
  • Product – determine if the product can meet all the specs on a statistical basis.
  • Compliance – verifies if all activities and results comply with written procedures and predetermined goals. Essentially, this is a “say what you do and do what you say” check.

Checklist: Indicators of stable production

A factory that manufactures products in accordance to strict processes is vital whether you buy spherical plain bearings or ball bearings. Consistent experience with the final product should be the result of an atmosphere that adheres to standards for everything from prints and machinery to employees and the working environment. Below is a checklist overview:

  • PDM – The factory uses product data management, or PDM, which is a computerized system that saves all product specifications, prints and customer information.
  • Employees – Factory workers are well trained and have the proper qualifications.
  • Gauges – The R&R of the instruments need to meet 10% max and be calibrated. The process capability index Cpk meets 1.33, 1.67 or other predefined goals.
  • Machinery – Machines are automatic or robotic, well maintained and periodically checked for capability.
  • Materials – Raw materials meet specs on prints.
  • Environment – The temperature, moisture, cleanliness and lights are suitable for machines, people and gages.

Red flag

A factory that lacks on-site testing capabilities is not verifying the bearing’s performance or service life, and as a result, unable to confirm quality. Look for equipment that tests chemical elements, microstructure, carbide non-metal inclusive or hardness. Without it, production parts are at risk of failing during use.

At a minimum, your bearing manufacturer should be able to test bearing steel, metallurgy, seal dust proof and grease leakage, and noise and vibration. A good manufacturer also has instruments to measure the bearing’s geometry and service life.

Nearly 60% of quality is determined by metal metallurgy, heat treatment and special characteristics.


A solid quality assurance system is essential. Who has certified the factory? It should be a European or Western entity. Certification from just a Chinese-based authority is not enough to ensure quality and performance. Understand that TS16949 certification has more effective quality control standards than ISO 9000.

If the suitable quality assurance system is running effectively, and if each process capability index Cpk is more than 1.33, 1.67 or meets the predetermined goal, the product quality will be consistent.

What other companies are saying

Manufacturers receive scorecards from their customers, which are similar to report cards. They grade everything from quality and delivery to PPM and risk reduction. Ask to see their supplier scorecards from either the current or most recent quarter, and measure them against the same time period for the previous year and your own standards.

It’s also important to ask for a list of current clients for reference checks. You should recognize company names on the lists and/or their products. Call to discuss their experience with the plant and ask how much of their inventory is produced by the source.

Bottom Line

In the end, your comfort level with a manufacturer will depend on what you see, not what you are told. Conducting an in-person audit shows you the materials, heat treatment, testing and lab centers, and most importantly the management and quality control system. The differences between factories will be striking and the elements you see will decide bearing quality and consistency.

It is important to note that CCTY is a Chinese company that owns and operates its own facility in Zhenjiang, China. So all aspects of the production are controlled.