Alpha Core Bits
Alpha Tools is a leading manufacturer of premium quality diamond core drill bits and make both wet core bits and dry core bits in sizes ranging from 3/8" to 2".
$97.15 to $141.53Shipping: FreeAlpha High-Speed Dry Core Drill Bits are designed for use on drills and grinders with 5/8” -11 spindles and are ideal for dry coring granite & engineered stone.
$85.38 to $120.75Shipping: FreeAlpha Wet Core Drill Bits are great for drilling the faucet-mounting holes in countertops and vanities and can be used to make clean rounded corners for square or rectangular sinkholes.
Diamond hole saws and core bits can either be operated on a drill with a 3/8" or 1/2" chuck, or a variable speed grinder. Drills will typically be a single speed, ranging from 500-1,200RPM. Running a diamond hole saw or core bit on a drill will cut material slower than a variable speed grinder, but are safe for operating most sizes up to 4" (maximum safe speed for 4" bits is 1,000 RPM).
Variable speed grinders allow for faster cutting of material. However, when running a diamond hole saw or core bit on a variable speed grinder or polisher, the RPM you use will depend on the size of the bit. Optimal RPM speed for faster cutting for bits that are 1" or smaller is 4,000 RPM. Optimal RPM speed for bits 1-1/8" - 3" is 1,300-2,000 RPM. Standard 4" and 5" variable speed grinders start at 3,000 RPM, so if you have larger bits that require lower speeds, you may use a 7" to 9" variable speed grinder with a starting RPM of 600-900.