Automotive Bearings are designed to withstand extreme heat and pressure. They are made of alloy materials such as copper, brass, bronze and steel. These bearings can be found in the tire section of your vehicle, but they also protect against vibration and noise when you are riding down the road over uneven pavement or rough roads. Our automotive ball bearings are 25 millimeters in diameter and made of chromium steel. They measure five millimeters thick and have a wide load-carrying capacity. The Mild Steel Three Wheeler Chrome Finished is a great product. It has gone through extensive testing to ensure this product meets the highest quality steps.