Chainsaw

A **chainsaw** is a tool used to cut wood, powered by a motor that drives a circular chain made up of numerous connected sharp metal teeth. A chainsaw has two main components: a saw blade integrated into a chain that runs along a long metal guide bar, and a one-cylinder gasoline engine. The chain, consisting of approximately thirty sharp steel teeth, moves around sprockets. Inside the engine, the piston moves up and down the cylinder, pushing a connecting rod that rotates a crankshaft. The crankshaft turns gears, which are connected to a sprocket that drives the chain, causing it to spin around the guide bar. The modern chainsaw, as commonly used in the timber industry, was originally developed in the late 18th century by two Scottish doctors for the excision of diseased bone. Chainsaw use poses significant risks of serious injury. A common hazard is kickback, which occurs when a chain tooth at the tip of the guide bar catches on wood without cutting through it. This causes the bar, with its moving chain, to snap upward in an arc toward the operator, potentially leading to severe injury or even death.