#7760 Extra duty pad: This pad is designed for welding spatter cleaning, heavy rust removal, discoloration removal, prior to painting for putty cutting. Old paint, color removal with surface finishing, it does the work as like as other pads, steel wool, wire brushes, coated abrasive sheets etc. # 7440 Heavy duty pad: 7440 is actually what you need for the industrial cleaning and finishing job call for tough, long-lasting action. It does the work as much as other pads, steel wool, wire brushes, conventional abrasive etc. cannot do, such as we