Just because your saw is for example an 18" Stihl  doesn't mean it's the same chain as fitted to an 18" Ryobi, or Husqvarna. Chainsaw manufacturers use different types of chain which are not always interchangable.

When ordering please ensure the chain has the same amount of drive links as in your old chain and is to the same specification

The Drive Links are shown above and are avilable in different widths (thickness's)  Too wide and they will not fit in the guidebar groove, too narrow and the chain will flop from side to side   

To determine which chain you require the widths are as follow: 0.43"(1.1mm) 0.50" (1.27mm-1.3mm) 0.58" (1.5mm) 0.63" (1.6mm) and then of course they come in different pitches, the most common being, 3/8" .325" 404"

CONFUSED?  There is no need to be confused with a little thought and patience!

Usually there is a number on the drive link, this determines the type of chain. ie: a chain with 91 on the drive link tells us it is a 3/8" pitch chain with 0.50" width. A chain with 22 on the drive link tells us it is .325" and 0.63" width Etc Etc. With this infrormation all you need to know is how many drive links there are in your old chain  and then select from our comprehensive listings. Suggestion: remove the chain to count the drive links, trying to count them with the chain still mounted can be very difficult. There maybe other numbers on the drive link, click here for a range of numbers used by various manufacturers

You can also find information stamped on to the side of the guide bar. ie:  91 3/8" 0.50" 1.3mm 52DL. You would need to order chain type 91 with 52 Drive Links or 22 .325" 063" 1.6mm 62DL you would need to order chain type 22 with 62 drive links Etc Etc