Abstract: Device for mounting of attachments, toolholders and tools with cone and face application, especially for machining and turning centers with automatic or manual changers of tools with tapered shank, in particular with 7/24th taper, comprising a cone (1) for introduction in the spindle, a front part (2) centered in an aperture in the cone (1) and provided with a flange for application against the face of the spindle and a gripping knob (3) for assembly of cone (1) and front part (2). The gripping knob is connected to an intermediate non-deformable connecting device having structure to allow adjustment of the length thereof. The connecting device is connected to the front part thereby to secure the front part to the cone.