Unless moving or revolving components of machinery are in such a position or of such construction that they are as safe as they would be if they were securely fenced or guarded, the user shall cause -
(a) every shaft, pulley, wheel, gear, sprocket, coupling, collar, clutch, friction drum or similar object to be securely fenced or guarded;
(b) every set screw, key or bolt on revolving shafts, couplings, collars, friction drums, clutches, wheels, pulleys, gears and the like to be countersunk, enclosed or otherwise guarded;
(c) every square projecting shaft or spindle end and every other shaft or spindle end that projects for more than a quarter of its diameter to be guarded by a cap or shroud;
(d) every driving belt, rope or chain to be guarded; and
(e) the underside of every overhead driving belt, rope or chain above passages or workplaces to be so guarded as to prevent a broken belt, rope or chain from falling and so injuring persons: provided that the provisions of this paragraph shall not apply where, in the opinion of an inspector, no danger exists in the case of light belts owing to the nature thereof and the speed of operation.