Abstract: A rotating tool for the cutting of hardened workpieces is comprised of a base body made of steel and having a working surface. The working surface is coated with a homogeneous layer of an extremely hard material. The layer has a uniform thickness. The working surface has a plurality of microcutting grooves that extend parallel to one another and at an acute angle relative to a tangent of the working surface. Each microcutting groove has a cross-sectional profile with a cutting edge and a chip space. The extremely hard material is preferably boron nitride and the base body is preferably made of hardened steel.

Abstract: A method and a device for preventing thermal damage of workpieces during grinding are provided. According to the inventive method a two-flank rolling test is performed via a master pinion before the grinding process. The result of this two-flank rolling test is then used to calculate an effective maximum amount of material to be removed. Based on a permissible amount of material to be removed per time unit for the respective grinding tool a permissible rate of advancement of the grinding tool is calculated with the determined effective maximum amount of material to be removed. The calculated rate of advancement is then fed into the machine control unit.

Abstract: The present invention discloses a method and a device for preventing thermal damage of workpieces due to heat developed by a grinding process. According to the method the temperature increase at the surface being ground is determined and the resulting actual value is compared to a reference value which has been established under the same grinding parameters with a grinding disk that caused thermic damage to the reference workpiece. During manufacture, the grinding process with the respective grinding disk is interrupted as soon as a temperature increase has been detected that corresponds to the respective temperature causing thermic damage. The reference value is determined such that it includes a certain safety margin. The determination of the actual value and the reference value may be accomplished by using geometric deformations of the workpiece that result from the temperature increase due to the grinding process.