This Diamond Core Drill Bit has 1 1/4 - 7 UNC Thread for Core Drilling Machine or with SDS Max Adapters. Sintered Diamond Core Bits are also known as Diamond Hole Saws. These are professional quality, heavy-duty diamond drill bits designed for use on Cement Block, Concrete, Brick and much more. Sintered diamond drill bits have the diamonds embedded into the metal of the Hole Saw teeth or continuous edge rather than merely "bonded" to the outside / tip. As the teeth wear down over continued use new diamonds come to the surface of the teeth. Sintered diamond drill bits are heavy duty bits designed for long life. Generally, sintered bits will have a long life of 20 to 30 or more times the life of a bonded Grit type diamond drill bit if used properly. The heavy-duty design provides long life when drilling in hard materials such as Brick and Concrete. Water is recommended for coolant and lubrication.