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Brake Drum


A brake drum (brakedrum), a component mounted on a car’s wheel hub that rotates with the wheel, is part of a drum brake system.


The material of the brake drum is generally HT 200-300 (i.e. gray cast iron), the matrix organization is mainly pearlite and a small amount of ferrite and carburized body, the graphite is mainly A grade, the form is long flake, the length grade is 4-6, which plays the role of heat dissipation, increase the friction performance and reduce the brake noise.

Production process and raw materials

Casting is the usual production process for brake drum blanks; the main raw materials required are generally pig iron, scrap steel and reheated iron, and some alloys such as Cu, Cr, etc. are added at the same time to improve the casting performance.

Working principle

When braking, the two pairs of half-moon brake shoes are subjected to the pressure exerted by the piston, which makes them stick to the inner wall of the drum chamber, and the wheel stops rotating through the huge friction force generated between them to achieve the purpose of braking.