The coefficient of friction tester is a measuring instrument used to measure the static and dynamic friction coefficients of materials such as plastic films and sheets, rubber, paper, cardboard, woven bags, fabric styles, metal composite belts for communication cables and optical cables, conveyor belts, wood, coatings, brake pads, wipers, shoe materials, tires, etc. when sliding. By measuring the smoothness of materials, the production quality and process indicators of materials can be controlled and adjusted to meet the requirements of product use. In addition, it can also be used for measuring the smoothness performance of daily chemical products such as cosmetics and eye drops.