How to Replace a Jointer Blade

When the knives on a jointer become too dull to use or get nicked, your first impulse may be to buy a new jointer. You wanted a bigger one anyway, and the idea of trying to adjust all those blades is a bit daunting. With a little patience and the right tools, you can save yourself some money. Replacing the knives on a jointer is exacting but not impossible. Follow the steps below and you'll feel a sense of accomplishment and be able to use the money you save to buy material for your next project. Set knives using straight edge Step 1Unplug the jointer. Test the on/off switch a couple of times to make sure you have the right power cord. Step 2Loosen and remove the old knife. Place the new knife in the cutterhead. Tighten the set screws or jam nuts enough to keep the knife from falling out but loose enough to allow for adjustment. Step 3Place the straight edge of the knife on the jointer's outfeed bed extending over the cutterhead. Step 4Rotate the cutterhead until the knife is in the top dead-center position. At the highest point in its arc, the blade should just touch the bottom of the straight edge. Step 5Check the blade's position across the width of the outfeed table. When it touches the straight edge without lifting it off the table across the width of the bed, tighten it and check again. Set knives using dial gauge Step 1Unplug the jointer. Test the on/off switch a couple of times to make sure you have the right power cord. Step 2Loosen and remove the old knife. Place the new knife in the cutterhead. Tighten the set screws or jam nuts just enough to keep the knife from falling out. Step 3Place the dial gauge on the outfeed table and adjust it to zero. Rest the base on the outfeed table and place the probe over the knife. Step 4Rotate the cutterhead until the knife is in the top dead-center position. Adjust the knife until the gauge reads zero across the entire width of the blade. Tighten the blade in position and check again.