Improved Design and Chemistry for Brake Drum Life

In a continuing study of brake drum life it was found that both design and chemistry are major factors in developing better performance. Under test conditions, centrifugally cast composite drums gave better performance than static cast drums for the same weight. A direct relation also was ob served between brake drum life and brake drum weight. However, the optimum weight has not been established yet to get maximum brake drum life. Important factors affecting life of cast iron brake drums are hardness, alloy composition, and structure of cast iron. The alloying element chosen should produce a structure that is nearly 100% pearlitic, free from carbides, and a random dispersion of flake graphite.