... very long life Diamond Core Drills in 1-1/4" UNC Connection Thread.For wet cutting very wide range of building ... connection thread, such as 1/2"BSP, 1-1/4"UNC, 5/8", PIXIE, M16, M22, M27 and ect....Available all ... .Certificate of ISO 9001: 2008 Connection Thread 1-1/4" UNC Wet Diamond Core Drill, Diamond Bit