When choosing a saw chain, you first need to know the pitch, the gauge and the number of drive links. Once you have these, everything else about the choice is basically about what you prefer.
Pitch is the average distance between two rivets on the saw chain. Its value (1/4", .325", 3/8" or .404") is commonly displayed on the guide bar. If you can not find it, our best advice is to let your dealer measure your old saw chain, as this is a bit tricky to do.
Gauge is the thickness of the drive links, and it is important to know this in order to make the saw chain fit correctly into the guide bar. The gauge (.043", .050", .058", or .063") is, like the pitch, probably displayed on the guide bar. If not, we recommend you to let your dealer measure the gauge on your old saw chain.
The length of a saw chain is determined by the pitch and the number of drive links. This is normally not printed anywhere on the bar or elsewhere on the product, so the links on the old saw chain need to be counted.
Putting a more aggressive saw chain on a standard saw will never give you a better performance. It is like putting shark teeth on a piranha – the bite will not get any better.
If you make sure that your saw chain and saw match each other perfectly (aggressive saw chain for an aggressive saw, and so on), your cutting equipment will always deliver its maximum performance.