The concrete diamond wet core drill bit is a kind of diamond tools which is used for core drilling, in other words, the cutter to remove a cylinder of concrete, asphalt or other materials. The idea for making holes with a medium or large diameter. For small diameter, the core drill bits are recommended to fix into a hand-held core drill motor. For diameter above 300mm, we recommend to fix core drill bits to rig-mounted core drill motor cause making big holes require for strong power and high torsion of the machine, operators can’t bear its performance and may get harm. For wet core bits, it is mainly used for the professional constructor in construction and it must add water to cool down the temperature that heated because of fast drilling speed and friction of concrete and core bits. It is proposed in a wide choice of diameters, from 12 up to 600 mm. The most popular working length in the market is 450mm. And the fitting thread is 1 1/4" -7 UNC.