Two types of chisel teeth in chain saw chains are defined by their shape and the shape of the file used to sharpen them. Chain saw chains are classified according to the number, spacing and angle of their teeth.
The square tooth, also called chisel tooth or flat top, is very square with a flat back and flat top. The chisel tooth chain is commonly preferred for sawmilling involving softwoods. This type of tooth is used on three kinds of chains.
The semi-chisel tooth is a less-aggressive cutter than the chisel. This type of tooth is more tolerant of dirt and dust and stays sharp longer. A round file, along with a file guide, is used to sharpen a semi-chisel chain.
The standard chain or full house has the most teeth. Chisel teeth in a standard chain can be at a 35-degree angle for a smooth cut. This chain is known as a crosscut chain. The Oregon rip chain has teeth at a 10-degree angle to produce a smoother cut than the crosscut.
On a semi-skip chain, half of the teeth are close together, as in the full house. The rest of the teeth are full skip. The semi-skip chain has a cutter sequence of one left-hand cutter, two tie straps, one right-hand cutter, followed by one tie strap, for the entire length of the chain.
A full-skip chain has half the number of teeth as the standard chain, and all are evenly spaced. This type of chain requires a large chain saw to drive it. Because there are fewer teeth, more power is needed to produce a rough lumber cut with this chain.
The most important parts on a chain saw are the chain and the bar. Keeping the teeth sharp and the bar clean makes cutting much easier for the chain saw motor and operator. At some point the chain will need to be replaced, depending on the frequency of use. Chains can be purchased in pre-cut lengths or in rolls of 100 feet.