§3583. Portable Abrasive Wheels.
Where the nature of the work is such as to entirely cover the side of the wheel, the side covers of the guard may be omitted. (2) The spindle end, nut, and outer flange may be exposed on portable machines designed for, and used with, Types 6, 11, 27, and 28 abrasive wheels, cutting-off wheels, and tuck pointing wheels.