Science, Tech, Math › Animals & Nature Important Parts of a Chainsaw Chainsaw Parts Essential for Operation and Safety Share Flipboard Email Print OSHA Animals & Nature Forestry Tree Identification Basics Arboriculture Tree Structure & Physiology The Science Of Growing Trees Conifer Species Individual Hardwood Species Pests, Diseases, and Wildfires Tree Planting and Reforestation Amphibians Birds Habitat Profiles Mammals Reptiles Wildlife Conservation Insects Marine Life Dinosaurs Evolution View More By Steve Nix Forestry Expert B.S., Forest Resource Management, University of Georgia Steve Nix is a natural resources consultant and a former forest resources analyst for the state of Alabama. He is a member of the Society of American Foresters. our editorial process Steve Nix Updated March 01, 2019 There are 10 typical parts of a chainsaw identified and illustrated. Occupational Safety and Health Administration (OSHA) requires that the chainsaw have the parts identified in bold italic text. Chainsaws placed into service after February 9, 1995, must also meet the requirements of ANSI B175.1-1991, safety requirements for gasoline-powered chainsaws. 01 of 10 Chain Catcher The chain catcher (figure 1) is a metal or plastic guard designed to prevent a broken or derailed chainsaw from striking the operator. 02 of 10 Flywheel The flywheel (figure 2) is a weighted wheel that controls engine speed and assists in cooling the engine. 03 of 10 Clutch The clutch (figure 3) attached to the chain sprocket, is the connector that controls the driving part of a chainsaw. 04 of 10 Decompression Valve The important decompression valve (figure 4) releases saw compression which allows easier starting. 05 of 10 Anti-vibration Handle System The anti-vibration handle system (figures 5 and 7) handles shocks is recommended by OSHA to limit ergonomic stress to the operator's hands, arms and joints. 06 of 10 Handguard The handguard (figure 6) is a defensive plastic shield that protects a user's hands from kickback. 07 of 10 Muffler The muffler (figure 8) is a hearing protection device used on chainsaws to reduce engine noise. 08 of 10 Chain Brake Adding a chain brake (figure 9) to all chainsaws was a safety requirement enabled in February 1995. The function of the chain brake is to stop the chain if kickback occurs to prevent user injury. 09 of 10 Throttle The throttle (figure 10) regulates a saw's RPMs by increasing or decreasing the volume of fuel to the cylinders. The chainsaw will stop the chain when pressure on the throttle is released. 10 of 10 Throttle Interlock The throttle interlock (figure 11) locking mechanism prevents the throttle from activating until the interlock is depressed.