Abstract: An apparatus for forming serrated edges in wooden panels for interengagement with abutting panels in a wooden I-beam assembly comprises opposed sets of broaches operable for cutting a toothed serration pattern cleanly and accurately in opposed edges of a stack of up to 40 such panels simultaneously. The panels are loaded in infeed means of the apparatus which transports the stack into position for broaching. The stack of panels is aligned laterally by lateral stack alignment means upon placement of the panels in the infeed means. Longitudinal stack alignment means aligns the stack longitudinally when it is transported by the infeed means to a position for broaching. During broaching the stack is supported on opposed anvils in a manner for forming the serrations symmetrically with respect to each end of the stack, hold down means clamps the stack on the anvils, and actuation means drives the broaches downwardly.