A Delta miter saw can cut a wide variety of materials with one table top. Like any other saw, the Delta saw is only as good as the blade you are using. Dull or bent blades require replacement. Replacing the blade on a Delta miter saw is slightly different than some other brands and requires raising the lower guard completely out of the way. Replacement blades are available at home improvement centers.
Unplug the Delta miter saw power cord from the wall outlet. Raise the cutting head to the up position. The cutting head is the portion of the saw with the blade and handle.
Locate the small screw on the side of the upper blade guard that secures the lower blade guard. The lower blade guard is the plastic guard that pivots as you cut through material. The lower guard has a slot track that rides over the head of the screw. Remove the screw with a Phillips head screwdriver.
Rotate the lower cover to the rear of the cutting head. Locate the spindle lock on the motor side of the cutting head. There is a small hole with an Allen head bolt in the center of the motor drive casing. Insert an Allen wrench into the bolt to lock the spindle.
Loosen and remove the bolt securing the blade to the spindle using a wrench, while holding the Allen wrench to prevent the spindle from turning. Remove the blade washer and blade from the miter saw.
Place a new blade onto the saw, inserting the saw spindle through the center of the blade. Place the blade washer over the spindle, and thread the securing bolt into the spindle. Insert the Allen key into the spindle lock bolt and tighten the blade bolt with a wrench.
Pull the lower guard down, and install the lower guard securing screw through the slot track on the guard and into the hole on the upper guard.