Depth stop supported by ball bearing with exchangeable guide bushings for FAMAG Forstner bits and Bormax®. The depth stop is mounted on the stem of the drill bit and the drilling depth has to be adjusted. This makes it possible to drill stud holes with exactly the same depth at all times. The bushings are rotatably supported by ball bearings and thus produce no disturbing marks on the workpiece surface. For larger drilling depths, it is possible to mount the guide bushing in reverse form, so that you can reach a larger adjustment of the depth stop.