Product details:

-5/8-11 thread fits on most popular high-speed grinders; -Use on the job site without using water; -Aggressive cutting on granite and engineered stone; -Maximum speed 11,000 RPM. DAMO Dry Core Bits are designed for use on the job site without using water. They fit on high-speed angle grinders with a 5/8 -11 spindle. Adopting the Vacuum Brazed Tech., they provide the best cutting performance and can drill through the toughest 1-1/4 granite or engineered stone countertop. They can be to drill the faucet-mounting holes in countertops and vanities. They can also be adapted for use in construction trades wherever holes are needed for water, gas and electrical piping, especially when natural stone, concrete or ceramic tile is already installed. Available in 1/4,3/8,1/2,3/4,1, 1-1/4, 1-3/8,1-1/2,1-3/4,2and 2-1/2 sizes. You may buy seperately our core bits adapter to use with the normal electric hand drills which take 3/8 shank.