Determining the type of chainsaw chain you need depends on the type of wood you want to cut. A type Y and S chain have no significant differences other than the letters' significance in the serial number of a chainsaw manufacturer. The Y or S in the serial number of a chainsaw chain signifies some feature of the chain. The chainsaw type is really determined by the way it cuts and is identified that way.
The Y on a chainsaw chain identifies a feature of the chainsaw chain manufactured by Oregon Industries. A semi-chisel or chisel type Oregon chain uses a Y to identify the vibe ban of the chain. The vibe ban of a chain signifies how much that chain will vibrate when cutting. The manufacturer claims the Oregon Y chain has less vibration than the other types of chain the company makes.
Stihl uses an S to identify the cutting shape and any other special feature the chainsaw chain has. The S is found in the marketing number of the Stihl chainsaw chain. The numbering system can also be found in the part number of the Stihl chain. The S within the marketing number of the chain indicates the chain's cutter shape is a super or full-chisel type of chain. Another S in the marketing number indicates the chain is made for special cutting.
Most manufacturers market chainsaw chains as chisel, semi-chisel, safety, full-skip, semi-skip or special purpose machines. Each type is used to cut different kinds of wood. The chisel type chain cuts faster than the other types of chains, but dulls faster. The semi-chisel type chain stays sharp longer than the chisel type and performs better in abrasive environments, such as dirt or sand. The safety type of chainsaw chain has a low-kickback feature the other types of chains do not have. A full-skip chain is used in larger chainsaws because it has a two chain links between each cutting tooth, which allows the saw to run at higher revolutions per minute and cut faster. A semi-skip chain has only one chain link between each cutting tooth and is not as strong as the full-skip chain.
Each chainsaw chain type has certain features that allow the chain to react differently than the other types of chain. For example, the low-kickback feature found on the safety type chain minimizes the kickback of the chain when it hits something hard. The cutter shape also varies in the different types of chains. The cutter shape can be square or round. The chains also vary in length, pitch and number of drive links. When choosing a chain type consider how often you will use the chainsaw, what you will be cutting and how experienced you are.