FLEX WHEELS (TYPE 27) - Semi-flexible grinding and finishing wheels can be used for all types of material. Innovative concept combines advantages of depressed center grinding wheels and resin fiber discs. As heat builds up during use, the double reinforced wheel becomes flexible and pliable, conforming to the surface being ground. For use with aluminum, stainless, carbon steel, copper, brass, fiberglass, exotics and composites. Use with right angle grinders.