GB/T 39693.4-2025 is the fourth part of the series of standards for the determination of Hardness of vulcanized rubber or thermal plasticity rubber, which specializes in the determination of Shore Shore Durometer Hardness. The standard specifies the test principle, instrument requirements, operation steps and results of the method. It is suitable for the conventional Hardness detection of two types of rubber, which can unify the detection method and ensure the accuracy of data. It provides a reliable technical basis for the production quality control, performance evaluation and application adaptation of rubber products.