Yato Masonry Drill Bit Set 7Pcs 4, 5, 6, 8, 9, 10, 12mm is a premium quality product. It consists of the 7 most common used sizes: 4mm, 5mm, 6mm, 8mm, 9mm, 10mm, & 12mm and is ideal for use on concrete, wall, bricks etc. It has a 40Cr HRC 47 drill body and YG-8C HRC 89-90 drill tip.