In our business, partnerships are extremely valuable. One of our partners is ZEN Shanghai – the group was founded 1992 in Düsseldorf, Germany, specializing in manufacturing German industry standard bearings in China. Almost 30 years later, ZEN group sells over 6.000 products on six continents in 18 countries with 22 distributors and six warehouses.  So that you can get to know the company a little better, we had an enlightening chat with Yago Zens, the head of quality control at ZEN Shanghai.

How long have you been working at ZEN?

Zens: “I’ve been working at Zen for 26 years now.”

What position do you occupy at ZEN? What are your tasks and responsibilities?

Zens: “As the head of quality control at ZEN Shanghai, I am charged with assuring that all ZEN bearings meet the DIN quality standards along the manufacturing process. I also coordinate all activities at the ZEN Quality Control Centre, and I assure the quality of the goods at the warehouse and during the packaging and shipping process. “

To what extent does ZEN emphasize quality control in their manufacturing process?

Zens: “For us, quality is in our DNA. It is a mindset for all members of our team, and it’s integrated through each step of our manufacturing process, from the sourcing of our raw materials right through to the aftercare once the product has been delivered.

At ZEN bearings quality is king and that is why all our investments are destined to incorporate the best technology in our manufacturing and quality control process. We plan to invest $ 3.1 million over a 24-month horizon. Our aim is to offer our customers bearings of exceptional reliability, perfect performance and the long
life of a premium product. To achieve that, all our bearings are tested during and after the manufacturing process.

Over the years we’ve developed a sophisticated manufacturing process in which fully automatic assembly machines ensure to the millimeter the perfection of ZEN bearings. Once the bearings are finished, all our products are tested in the ZEN Quality Inspection Centre. Our in-house inspection centre covers more than 5,000 squares meters, featuring state-of-the-art testing equipment and a great team of highly qualified inspectors who are working every day to ensure a high level of quality.”

Can you take us through the steps of the ZEN quality control process?

Zens: „The ZEN Bearings quality control process involves several procedures, all of them as well our tolerances, are set to DIN Standards, certificated by the German TÜV.

• Visual inspection: An expert eye helps detect any material or assembly fault.
• Dimension Testing: A very strict tolerance check is performed on all bearing dimensions to guarantee that the products are according to the DIN standards.
• Noise Testing: Highly sensitive microphones measure and identify audible peaks of a rotating bearing. These peaks can indicate faults to the raceways or possible grease pollution.
• Vibration Testing: Using high, medium, and low range frequencies, the vibration test can identify a range of bearing defects, such as imbalance, play and misalignment.
• Radial Clearance Testing: Our machines are calibrated regularly to ensure the tolerances adhere to DIN standards certificated by the German TUV.
• Hardness Testing: The Rockwell test determines the hardness of the material by measuring the depth of penetration of an indenter under load.
• The salt spray test is a standardized test method used to check corrosion resistance of materials. It is an accelerated corrosion test that produces a corrosive attack on the tested samples to predict their corrosion resistance. The appearance of corrosion products (oxides) is evaluated after a period. Test duration depends on the corrosion resistance of the material the more corrosion resistant the material is, the longer the period in testing without showing signs of corrosion. The standard testing period for ball bearings is 120 hours. “

Your quality management system is certified with the ISO 9001 by TÜV Rheinland. What does this certificate entail?

Zens: “In our industry, the highest standard we can achieve for the Quality Management System is the ISO 9001 certification. This certification proves the accuracy, preciseness, and reliability of our quality control system. Also, it is a global benchmark that guarantees a total focus on customer service and continual improvement.”

What measures do you take when it comes to packaging your products?

Zens: “All our packaging is specifically designed to keep our bearings in optimum condition avoiding any damage. As a rule, we use a corrosion-resistant foil but depending on the characteristics of the bearing and on the customer ́s requirements, we adapt our packaging.”

What other measures do you implement to ensure the quality of your products?

Zens: “In addition to the DIN standards and the ISO 9001:2015 protocols, we implement our own checking procedures in our Chinese premises as well as in our global warehouses. This way we ensure that the bearings are in perfect conditions throughout the production and distribution process.”

How can customers get more information about a product and the company?

Zens: “You can find more information at www.zen.biz and on request, we can provide material certificates and material test certificates of course.”

We thank Yago Zens a lot for this informative interview and we look forward to our continued collaboration.