The following sections cover the basic guidelines for changing the rotary saw blades for each of these woodworking tools.
Inspect the motor and arbor of the saw as well as the dust guard for any excessive pitch build-up or collecting sawdust. If necessary, clean out these areas with a shop vacuum to ensure proper air flow through the dust collection port.
If your motor is equipped with a push-button locking mechanism for holding the blade in place during a blade change, rotate the blade by hand while gently pressing the push button until the blade locks into a solid position. If your motor is not equipped with a blade lock, your saw will likely be equipped with two blade change wrenches. Slide the end of one of the wrenches over the arbor nut to hold the motor shaft in place.
Position the remaining wrench over the arbor nut and twist the arbor nut to loosen the nut. Rotate the nut until it slides off of the arbor, followed by the arbor washer. Then slide the saw blade off of the arbor, taking care to notice the direction in which the carbide teeth are pointed. Install the replacement saw blade (of the same diameter) onto the arbor shaft, orienting the carbides in the same direction as the blade you removed, followed by the washer and the nut. After hand-tightening the nut, tighten the nut using the arbor wrenches. Then replace the insert and safety equipment before testing your blade.
Compound Miter Saw:
As with the table saw, your miter saw may have a locking button to secure the motor, or it may require a pair of arbor wrenches, depending on the design. Lock the motor in place with one hand and loosen the nut or bolt holding the washer and blade onto the arbor with the other hand. Set the bolt (or nut) and spindle washer aside.
Notice which direction the saw blade is oriented, then remove the blade from the arbor and slip the new blade into position, orienting the blade's teeth in the same direction as the blade you removed. Replace the washer and thread the bolt (or nut) onto the arbor and tighten to secure the blade. Then slide the blade guard back into place and tighten the screws to secure the blade guard.
Radial Arm Saw:
Once the blade is secure, loosen the nut with the supplied wrench. In my experience, using a circular saw's blade wrench can be a knuckle-busting experience. I prefer to keep a ratchet and socket set on hand to loosen the arbor nut, as you'll be able to apply a bit more torque and save your knuckles.
After loosening the arbor nut, remove the nut and arbor washer, then slide the blade off of the arbor (once again, noticing the orientation of the blade). Install the replacement blade with the teeth oriented in the same manner (cutting against the spin of the motor), followed by the arbor washer and arbor bolt.
TIP: In order to tighten the blade securely, you may need to place your locking pliers onto the new blade to hold it in place while tightening the arbor bolt.