This part of GB/T17037 specifies a four-cavity mold, that is, C-type GB/ISO mold, which is used for injection molding of small tensile specimens, and the specimen size is ≥60 mm×10 mm×3 mm (GB/T37426 —2019 Small and Medium Tensile Specimen Type CW13). This section is applicable to the preparation of reproducible small tensile specimens by injection molding of thermoplastic materials.