The pneumatic products, electric products, gas-electricity products we produce, etc., all involve the use of some externally purchased raw materials and raw materials produced by ourselves. For the control of raw materials, we conduct corresponding tests based on whether there is abrasion, material quality, and material application. We conduct repeated sampling inspections through manpower. The importance of raw materials relates to the subsequent product assembly links and whether the testing procedures are performed normally. Otherwise, It will increase the cost of manpower and time, so in the purchase of raw materials, in addition to selecting high-quality materials, we also have hidden quality problems.