There are two kinds of chainsaw cutting teeth. One has a round tooth and the other has a square tooth. Round teeth can be identified by the way the back side is rounded and curves up on the top. The square tooth, or more commonly referred to as chisel tooth, has a sharply angled point and a flat top.
Number of Teeth
Chainsaw chains are also identified by the number of teeth and in what pattern they occur across the chain. The standard chain style has teeth that are close together, on every other guide link, and contain the most teeth of all the styles. One-half skip chains have half the teeth close together, like the standard chains, but the other half are a full skip. Full skip chains have a tooth every two guide links.
The gauge of chain also identifies the type of chain. The chain gauge is the thickness of the drive link, which connects to the guide bar. It is very important to match the thickness of your drive links with the width of the guide bar. Common chain gauges are 0.050 and 0.063 inches.
The distance between any three consecutive rivets measures the chain pitch. The pitch is important to identify because you must match the chain's pitch with the nose sprocket and drive sprocket.
Chain sizes are measured by counting the number of drive links on the chain. These numbers must match the length of your guide bar.
Chains can be expensive but they are the most dangerous part of your chainsaw. Use only chains recommended by your manufacturer and make sure they meet all the proper specifications. If a chain is improperly sized, it can break during cutting and hit the sawyer in the legs. Always follow safety guidelines when installing a new chain.