Depending on the chainsaw you are using and for which type of work, you will need a different type of chainsaw chain. Chains are sold based on four important factors: Pitch, Gauge, Drive Link count, and by application/user preferences.
This is not a straight-forward process and it is recommended that you take your chainsaw to the local authorized dealer so the correct chain can be established. They will need to determine if the chainsaw is used by a consumer or a professional, also they will need to determine the following:
Pitch
Pitch is defined as the distance between any three consecutive rivets divided by two. We offer 6 variants of pitch: 1/4", .325" mini, 3/8" mini, .325", 3/8" and .404".
Gauge
Gauge is defined as the width of the drive link that fits into the guide bar. We offer chains in 4 variants of gauge: .043/1,1 mm, .050/1,3 mm, .058/1,5 mm, .063/1.6 mm.
Length of the chain
To determine the "called" length of the chain you will need to count the number of drive links.
Other criteria
Other than the fit criteria (gauge, pitch, and length) chains have different characteristics (e.g., cutter profile and chain type) to fit different applications and user preferences.
The fit criteria (1-3) of the chain and bar are often printed into the guide bar side plate.