Was ctting a 7 x 1 inch thick hardwood board with the edge slightly untrue (1/8th) resting against the guard. 6 1/2 inches into the cut, the board reseated against the guard and grabbed the blade like the pads of a disk brake. Base plate casting broke where the radial arm is bolted. The radial arm and all flipped with jagged piece of broken base missing my forearm by a few 16 ths. The base casting (0,115 inch throughout) isn't obviously what it should be especially in areas of likely stress.