1. Check Surface Quality: If the machining precision of the universal ball joint is good, secondary surface treatment is unnecessary. Secondary treatment is used because poor surface cleanliness hinders electroplating. To remove these imperfections, a grinding wheel is typically used for polishing. However, please note that polishing immediately results in a loss of dimensional accuracy, which is noticeable to users. If accuracy is lost, users can check multiple dimensions; there will definitely be an error of 0.1mm. For mechanical products, everyone understands the significance of 0.1mm.
2. Flexibility: This is also easy to judge. Rotate the ball with your fingers. A good quality ball joint typically achieves a 4-6 second inertial rotation. Zhongnuo Universal Ball Joint Factory's products achieve a 5-second inertia. Our market research shows that 80% of manufacturers produce balls with around 3 seconds. Another important factor during rotation is noise, which will be discussed in point 3 below.
3. Noise: Noise is generated by several factors: 1. the precision of the ball cavity machining; 2. the ball's quality. Generally, surface polishing will result in significant noise, as insufficient machining precision necessitates polishing. For the bearings, we use high-precision bearing steel balls. Many manufacturers use low-hardness carbon steel balls. We've tested them, and bearing steel balls have 3-4 times the lifespan, twice the flexibility, and half the noise of carbon steel balls.
4. Precision: Customers can use calipers or micrometers to inspect 10 pieces. If the dimensional error of each piece is 0.03-0.1 mm, then the precision is known.