Maintaining your chainsaw blade is critical to the safety and efficiency of your saw. Anything sharp that rotates at 50 feet per second is something you want to keep in proper working order! And when it does come time to replace the chain, you want to make sure this is done correctly – an improperly fitted chain can injure or possibly even kill you next time you fire up your saw.
Getting the Correct Replacement Chain
There are nearly infinite combinations of types, sizes and features when it comes to chainsaw blades, making getting the right chain more complicated than it sounds.
You need 3 numbers, which you can hopefully find in your manual or on the saw itself: pitch, gauge, and the number of drive links.
Pitch is a measurement that describes how close together the links are on your chain. This doesn’t tell you the length of the chain or even how many links you have. You should see the pitch somewhere on your saw. It should be one of the following: 1/4″, .325″, 3/8″, 3/8″ low-profile, and .404″.
This is the thickness of the underside of your chain, the part that fits into the guide bar. This measurement has to be correct or no amount of effort will make your chain work properly. This number should also be displayed on your saw, usually toward the end of the guide bar. It will be either .043″, .050″, .058″, or .063″.
Number of drive links
Drive links are the notches or dull teeth on the underside of your chain that fit into the guide bar. They are what gauge measures the thickness of. And for some infernal reason, the number is NOT displayed on most saws. You also can’t go by the length of your chain. You must actually count the number of drive links in order to choose the correct replacement.
The first time you change your chainsaw blade you’ll therefore have to go through steps 1- 3 below before buying your replacement blade.
Steps to Changing Your Chain
Remove the side panel at the base of the guide bar. Your chainsaw should have come with a tool called a screwrench which you can use to unscrew this panel. Its probably held on by 2 nuts. Be sure and unlock your brake before doing this. If the brake is locked and it’s attached to the side plate, you’re going to have a really tough time getting the plate back on later.
Release tension from the chain by pinching the guide bar at the nose end and pulling away from the base of the saw.
Now that it’s slack, you can easily remove the chain from the guide bar. Now you can count the drive links.
At the base of your guide bar, you’ll see a tiny screw (it is parallel to the guide bar, not running through it). This is the tensioning screw, and you need to loosen it to make installing the new chain easier.
Thread your new chain around the clutch drum (at the base of the guide bar) and make sure the drive links have hooked into the sprocket and can turn the drum. Then thread them through the guide bar.
Restore the tension by again pinching the guide bar at the nose and pulling it away from the base of the saw. As you do this, make sure the adjustment pin (which is sticking out at the base of the bar) aligns with its proper groove.
Replace the side plate, but do not screw it in all the way yet.
Go back to the tensioning screw you loosened earlier, and tighten it to adjust the tension on the chain.
Finish tightening the side plate nuts.
You’re now ready to use your chainsaw again!