The 3M™ Fibre Disc Back-up Pads provide a sturdy support for fibre backed discs, which enhances the power of the abrasive when sanding, deburring and finishing. It is made of a tough plastic material, which gives support evenly across the surface of the disc. These hard density back-up pads are strong yet still slightly flexible, which allows for smooth application of abrasive discs to metal surfaces.