How Much Does a Brake Drum Weight on a Semi Truck?

A brake drum is an essential part of a semi truck’s braking system. It is a metal disc mounted to the axle of the truck, and is attached to the brakes.

The drum rotates when the brakes are applied, and its action causes the brakes to slow or stop the semi truck.

The weight of a brake drum on a semi truck can vary depending on its size and construction. Most brake drums for semi trucks weigh around 30 pounds, although some may be as light as 20 pounds or as heavy as 40 pounds. The weight also depends on whether it is cast iron or alloy steel.

Cast iron brake drums are typically heavier than alloy steel drums, due to their higher density. Cast iron drums are very strong and durable, making them ideal for heavy-duty applications such as commercial trucks and buses. They provide great braking power, but they can be prone to wear over time.

Alloy steel brake drums are lighter than cast iron drums, but they provide less stopping power because of their lower density. They are usually more affordable than cast iron drums, and they tend to be more resistant to wear over time.


In conclusion, a brake drum on a semi truck typically weighs between 20 – 40 pounds depending on its material and size. Cast iron drums are usually heavier than alloy steel drums but provide better braking power while alloy steel drums tend to be more resistant to wear over time.

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Susan Delgado