3.—(1) The cutter or cutters of every horizontal milling machine shall be fenced, by a strong guard properly adjusted to the work, which shall enclose the whole cutting surface except such part as is necessarily exposed for the milling operations.
(2) The guard shall either:—
(a)be provided with adequate side flanges; or
(b)extend on each side of the cutter or cutters to the end of the arbor, or to the arbor support, or to a distance of not less than half the diameter of the cutter,
provided that sub–paragraph (2) of this paragraph shall not apply to cutters used for face milling.