Bihui Core Bit Set of 4, 25 to 70 mm

The BIHUI diamond core bit set holds 4 bits, 25, 40, 60 and 70 mm in diameter. The bits carry a diamond layer made by the newest method: the diamonds are bonded to the bit by vacuum brazing. That method lets you drill holes very fast and without effort even in hard porcelain stoneware. Drill at medium speed on the angle grinder. Before drilling, put a wet pad inside the bit, cut to the size of the bit beforehand. Start the hole and keep drilling while constantly changing the tilt from side to side. Do not lean hard on the surface of the tile. Under no circumstances cool it with a sudden change of temperature. Do not drill a whole run one after another, let the bit rest. The gem of the set is the good case for storing the bits. A mid-diameter bit will do 40 – 50 holes on average in 10 mm porcelain stoneware. No warranty