Jinnge's reliable brake drums are crafted from FC300 gray cast iron, boasting a tensile strength of 300MPa and excellent thermal conductivity. The casting process uses high-pressure molding to achieve a density of 7.3g/cm³, reducing the risk of porosity by 90%. The inner surface is finish-turned to a roughness of Ra1.6μm, ensuring smooth contact with brake shoes. Each drum undergoes magnetic particle inspection (MPI) to detect micro-cracks, and dynamic balance testing at 3,000rpm. These drums are suitable for heavy trucks carrying up to 40 tons, with field data showing they maintain dimensional stability after 500,000 km of use.