Rather than relying on channel action like normal bits core bits have a central pilot bit that holds the bit in place while the outer sections of the bit cuts a hole through stone.
Marble hole drill bit.
Hole bits or core bits are specially designed drill bits that are tipped with either diamond or carbide.
Marble core bits are a hollow cylindrical bit that is the cutting part of a core drill.
Marble drilling bit self centering marble drilling bit creates the perfect indentation to keep marbles in place on a board.
Yotino 15pcs diamond drill bit set 0 24inch 6mm small diamond hole saw set hollow core drill bit set for glass ceramics porcelain ceramic tile marble 3 9 out of 5 stars 116 9 99 9.
These core bits are made up of a concentration of diamonds and metal bonds in order to cut the hard surface of the granite.