Grinding tool for trapezoid grinding the wafer

It includes an annular wheel having a central hole to be applied to attach the wheels of annular spindle, grinding tool for a wafer to trapezoidal grinding in profiling machine. Wheel has at least two grooves are arranged on the outer edge of the wheel, the groove is sized to receive the outer edge of the wafer. At least one of the grooves is applied to rough grinding of the wafer. At least one other groove is applied to a precision grinding of the wafer.