Saw chain or "cutting chain" is a key component of a chainsaw. It consists of steel links held together by rivets, and superficially resembles bicycle style roller chain, although it is closer in design to leaf chain. Its key differences are sharp cutting teeth on the outside of the chain loop, and flat drive links on the inside, to retain the chain on the saw's bar and allow propulsion by the engine or motor.
Saw chain (and chainsaws generally) are used for cutting wood. This may be for harvesting trees for pulp or timber, for tree surgery, or for processing firewood.
Whether for handheld chainsaws, mechanical timber harvesters or chain routers, has undergone dramatic development since its invention. Modern chains designed for high power, high speed sawing applications will vastly outperform older designs, while allowing a far greater degree of safety and reliability in use.