A cutting tool, such as a turning tool, includes a clamping holder on which a clamping shoe is secured. The clamping shoe has a curved surface projecting member adjacent one end for securing a cutting bit in a recess in a first surface on the clamping holder. The projecting member seats within a shaped recess in the cutting bit. Guide cams are located adjacent the opposite end of the clamping shoe and contact a second surface on the clamping holder inclined relative to the first surface. A clamping bolt located between the projecting member and the guide cams secures the clamping shoe to the clamping holder. A spring encircling the bolt biases the clamping shoe outwardly from the clamping holder. A pin member is mounted in the second surface of the clamping holder and engages between the guide cams as protection against turning the clamping shoe about the axis of the clamping bolt.