A chain block is a piece of equipment used to lift heavy items. The typical block, also known as chain falls, consists of two grooved wheels with a chain wound around them in the same fashion as a block and tackle. As the chain is pulled in a certain direction, it winds onto the wheels and the end of the chain that has a hook attached to it begins to rise and easily lifts an object.

The chain wound around the two wheels creates a simple machine that uses the leverage and the increased lifting ability created by the two wheels to lift heavy weights. Commonly found in auto repair garages, a chain block is often used to remove automobile engines from the chassis when repairs or replacement become necessary. The block allows a single person to raise an entire engine up and away from the automobile chassis. Conversely, the block also allows a single worker to install an entire automobile engine without assistance.