... long life 3, Full range of sizes Diamond triple core drill bits with brazed segments for concrete wet use1 ... customers can change any of them to reduce cost2, For drilling concrete, reinforced concrete , concrete products ,masonry walls3 ... 5mm, 2mm, 2.5mm, 3mm.7, All kinds of thread adaptors or connections in 1-1/4"UNC, 1/2"BSP,5/ ... upon request. Diamond core drill bits for concrete triple 3 sections