Miter kickback is a condition that can occur when cutting boards with a miter saw. It happens when the board being cut binds against the blade, causing the blade to stop and the board to kick back.
Miter kickback can be caused by several factors. One is using a blade that is too small for the material being cut. Another is not supporting the material properly. The material can also bind if it is not cut at a 90 degree angle.
To avoid miter kickback, be sure to use a blade that is the right size for the material. Also, support the material properly so it does not bind. Be sure to make cuts at a 90 degree angle. If kickback does occur, stop the saw immediately and unplug it.