chainsaws

Chainsaws are portable power saws that use a rotating chain with sharpened teeth to cut through wood. They are typically hand-held and powered by a small internal combustion engine or an electric motor, making them common in forestry, logging, firewood processing, and rescue operations.

Key components include the guide bar, which supports the chain; the cutting chain itself; the engine or motor; a clutch, sprocket, and drive system; and safety features such as a chain brake and anti-vibration mounts. Bar length varies widely, from about 8 inches for pruning to 20 inches or more for general use, with professional models reaching even longer bars. The chain's pitch and gauge determine compatibility with the bar and drive sprocket.

Most gasoline chainsaws use two-stroke engines that mix fuel and oil for lubrication; cordless models rely on batteries; corded electric versions use mains electricity. Typical uses are felling trees, bucking felled trunks, limbing branches, pruning, and cutting firewood. Gasoline models offer mobility, while electric versions are quieter and emit no exhaust.

Safety is essential: operators wear protective equipment such as helmets with face shields, hearing protection, gloves, cut-resistant chaps, and sturdy boots. Kickback can occur if the bar tip touches wood or another solid object; many saws include a chain brake to curb this risk. Proper starting, handling, and maintenance procedures are required, and recreational use should avoid bystanders.

Maintenance includes keeping the chain sharp and correctly tensioned, filling the bar oil reservoir, cleaning or replacing air filters, spark plugs, and fuel/oil mixtures on two-stroke engines. The development of chainsaws began in the 19th century with early chain saws, with modern portable models popularized in the early 20th century by manufacturers such as Stihl and Husqvarna.