Abstract: A honing or grinding tool and a measuring device used therewith is descri The honing tool includes a cutting element, a cutting element support and a layer disposed between and connecting the cutting element and the cutting element support. The layer includes a substance embedded therein which selectively absorbs and/or emits electromagnetic radiation at specific wavelengths, such that the substance is exposed when the cutting element is worn off and detected by the measuring device.

Abstract: The boring and milling head (11) is designed to receive a boring and mill tool (91) provided with a clamping device (55) having a hollow clamping cone (57) and a conical clamping wedge (61), the device being connected in order to resist torsion, to a drive element (21) which may be coupled with a rotary driven boring bar or with another similar mounting. In order to perform a boring and milling in a single operation with the overmentioned boring and milling head (11), without having to change the tool and/or the position of the boring bar or of the work piece, the longitudinal axis of the clamping device (55) containing the boring and milling tool (91) may pivot with respect to the rotation axis (88) of the drive element (21).