THESE ALL ALUMINUM BUTTONHEAD POP RIVETS ARE EXCELLENT FOR FASTENING 2 PIECES OF MATERIAL TOGETHER OF VARIOUS THICKNESSES. THESE RIVETS ARE USED FOR BLIND FASTENING WHERE THERE IS NO ACCESS TO OPPOSITE SIDE OF THE WORK. THE LOW PROFILE HEAD IS TWICE THE DIAMETER OF THE RIVET BODY, PROVIDING ADEQUATE BEARING SURFACE FOR NEARLY ALL APPLICATIONS. ALUMINUM RIVETS SHOULD BE USED WITH SIMILAR MATERIAL TO PREVENT GALVANIC CORROSION.