Zirconia alumina and aluminum oxide for up to twice the life of aluminum oxide wheels * Type 01 wheels are straight (also called flat) cut-off wheels, and are used for peripheral grinding * Rapid Cut wheels are centrally reinforced and have rough sides to provide a free cut with minimal binding * Reinforced design helps provide safety, strength, and straight cuts * Resin bonds soften under the heat of grinding, releasing dulled abrasive grains