Chainsaw

A chainsaw (or chain saw) is a portable mechanical saw, typically powered by a two-stroke engine. It is used for cutting trees, to fell snags, to cut firebreaks in wild land fires, and to harvest firewood. Special chainsaws are used for cutting concrete.

Parts
A chainsaw has several parts, including:

Engine — usually a two-stroke gasoline (petrol) internal combustion engine, usually with a cylinder volume of  or electric motor. 
Drive mechanism — typically a clutch and sprocket. 
Guide bar — a long bar with a round end of wear-resistant alloy steel usually  in length. An edge slot guides the cutting chain. 
Cutting chain — Usually each segment in this chain (which is constructed from riveted metal sections similar to a bicycle chain, but without rollers) features small sharp blades called teeth. The bottom of each link features a small metal finger called a "drive link" which locates the chain on the bar, helps to carry lubrication oil around the bar, and engages with the engine's drive sprocket inside the body of the saw. 

As chainsaw carving has become more popular, the makers of chainsaws are making special short, narrow-tipped bars for carving. These are called "quarter tipped," "nickel tipped" or "dime tipped" bars, based on the size of the round tip. After sometime the chainsaw chain gets dull.

References

Category:Gardening tools
Category:Saws