High quality mil spec GLASS BEAD made in the U.S.A. 5.5 on Mohs hardness scale. Quality GLASS BEAD is an excellent media to provide smooth, bright, contamination-free finishes. These hard round particles close up surface roughness and porosity by peening. This helps prevent corrosion, resist rust, staining and fingerprints, and provides a bright, tight new surface. Peening of most any surface (other than light sheet metal) can help its appearance and longevity, whether it is to be painted, plated, powder-coated, or left bare. Peening helps to combat stress-risers that can produce cracks and increase fatigue resistance to critical parts, retarding fatigue and fatigue corrosion. Being chemically inert, NON-TOXIC, containing virtually NO SILICA, GLASS BEAD will not leave any undesirable or ferrous residue on blasted surfaces. Uncontaminated spent media is ENVIRONMENTALLY HARMLESS. Some Uses of #10 GLASS BEAD: Change surface textures and finishes; Good for blending and final finish on aluminum sand castings as well as other metals; Good for texturing aluminum parts; Decorative reflective spheres for hobby use. Have further questions? Let us know -- We're here to help! - Tacoma Company