Toolholder assembly

A holding apparatus so that it can release a tool holder (25) with a stem (30) with locking surfaces, the apparatus comprising: (a) a support part tool (15) having a surface (35) da forward and an inner diameter (40) along a longitudinal axis (L), wherein the bore (40) intersects the surface (35) that faces forward and extends rearwardly from there for receive the shank (30) of the tool (25); (B) a movable pin (20) located inside the part of the tool holder (15) along a radial axis (R1) relative to the longitudinal axis (L) and having a first end (22) with a segment lock (65) with a bolt locking surface (70) of the bolt. (C) a movable nut (75) pivotally secured to the support piece tool (15) attached with thread to a second end (24) of the movable pin (20) and a locking segment (80) the nut with a locking surface (88) of the nut; and (d) in which the rotation of the mobile bolt (20) in a locking direction causes the actuating nut (75) moves toward the first end of the bolt (22) and clasping the locking surface (88) of the nut and bolt locking surface (70) for engaging the locking surfaces of the tool holder and the tool holder to lock the tool support piece (15).