Interface adapter comprising a first module (20, 220) and a second module, said first module holding a tool or a tool holder and said second module supporting a processing element for the rotating or static processing of work, - said first module (20, 220), when constituting part of a rotatable spindle or part of a chisel (220, 239), having therein a recess which includes, on the one hand, at least one section in a frustroconical or cylindrical shape and, on the other hand, an engagement surface (24, 224) or contact site acting axially, i.e. in the direction of the second module, and - the second module having a shank including, on the one hand, a conical, frustroconical or cylindrical section for engaging the frustroconical or cylindrical section of the first module (20, 220) and, on the other hand, at least one axially acting contact site or engagement surface for contacting the engagement surface or contact site (24, 224) of the first module (20, 220), with a bayonet-type lock provided between the recess of the first module (20, 220) and the shank of the second module, said lock comprising at least one fin (106, 115) provided on the shank, and with the first module (20, 220) having therein a tensioning element of which the front end engages a least one fin (105, 115) as the device is being placed under tension, characterized in that, - for being clamped in a spindle head of the spindle, fin of the bayonet-like lock has a first clamping flank of which the slope angle is smaller than 30 degrees, and in that - the fin of the bayonet-like lock has, for clamping the chisel (220, 239) in the chisel head, a second clamping flank of which the slope ranges between 50 and 80 degrees of an angle. - said first module (20, 220), when constituting part of a rotatable spindle or part of a chisel (220, 239), having therein a recess which includes, on the one hand, at least one section in a frustroconical or cylindrical shape and, on the other hand, an engagement surface (24, 224) or contact site acting axially, i.e. in the direction of the second module, and - the second module having a shank including, on the one hand, a conical, frustroconical or cylindrical section for engaging the frustroconical or cylindrical section of the first module (20, 220) and, on the other hand, at least one axially acting contact site or engagement surface for contacting the engagement surface or contact site (24, 224) of the first module (20, 220), with a bayonet-type lock provided between the recess of the first module (20, 220) and the shank of the second module, said lock comprising at least one fin (106, 115) provided on the shank, and with the first module (20, 220) having therein a tensioning element of which the front end engages a least one fin (105, 115) as the device is being placed under tension, characterized in that, - for being clamped in a spindle head of the spindle, fin of the bayonet-like lock has a first clamping flank of which the slope angle is smaller than 30 degrees, and in that - the fin of the bayonet-like lock has, for clamping the chisel (220, 239) in the chisel head, a second clamping flank of which the slope ranges between 50 and 80 degrees of an angle.