30 CFR § 56.14115 - Stationary grinding machines.
Stationary grinding machines, other than special bit grinders, shall be equipped with -
(a) Peripheral hoods capable of withstanding the force of a bursting wheel and enclosing not less than 270° of the periphery of the wheel;
(b) Adjustable tool rests set so that the distance between the grinding surface of the wheel and the tool rest in not greater than 1/8 inch; and
(c) A safety washer on each side of the wheel.