(1) Each tenoning machine must have all cutting heads, saws if used, and all exposed moving parts guarded. In the case of cutting heads and saws, the guard must be of solid metal.

(2) If sheet metal is used, it must not be less than ten U.S. gauge in thickness. If cast metal is used, it must not be less than three-sixteenths inch thick, or if aluminum is used, it must not be less than five-eighths inch thick. The hood of the exhaust system may form part or all of the guard. When so used, the hood must be constructed of metal of a thickness not less than that specified herein.

(3) Feed chains and sprockets of all double end tenoning machines must be completely enclosed, except that portion of chain used for conveying stock. At rear ends of frames over which the feed conveyors run, sprockets and chains must be guarded at the sides by plates projecting beyond the periphery of sprockets and ends of lugs.

(4) The rear end of the frame over which the feed conveyors run must be so extended that the material as it leaves the machine will be guided to a point within easy reach of the person removing stock at the rear of the tenoner.

(5) Single end tenoners, hand fed, must have a piece of sheet metal placed so that the operator's hands cannot slip off the lever handle into the tool in passing. Such guard must be fastened to the lever.