SHDIATOOL Dry Diamond Drill Core Bits 4pcs/Set Dia 20/25/35/50mm Vacuum Brazed M14 Connection for Tile Porcelain Granite MarbleQuantity: 4 piece; Diameter: 20mm+25mm+35mm+50mm; Diamond Height: 10mm; Total length: 60mm; Connection: M14 thread Designed for dry drilling in porcelain stoneware, ceramics, natural stone tiles, marble, granite, tiles, hard floor tiles and so on. Wet using can prolong its life High quality and temperature resistant diamonds ensure professionally clean and fast drilling. Vacuum brazing is the most effective and precise way of making diamond tools. It