This standard specifies the classification, technical requirements, test methods and inspection rules of Non-metallic paper-based wet friction materials, and covers marking, Encasement, transportation and storage requirements. It is suitable for friction elements of wet friction systems such as Motorcycle, Agricultural Machinery, Industrial Machinery and Automotive Wet Automatic Transmission. The standard aims to ensure the performance Stability and Reliability of friction materials in various wet environments, and to ensure that the product mass meets industry requirements by standardizing test methods and inspection procedures.