Abstract: A rake angle ? of a cutting blade 2a of a shaving tool 2 is set to a negative value and a flat surface 4 of an appropriate length is formed on a clearance surface 3. Even when center of the shaving tool 2 and center of a wire material 1 are displaced due to the negative rake angle, a cutting component force is applied in the direction in which the wire material 1 is returned to the center of the shaving tool 2. Since unevenness of a processing surface of a wire material surface generated by a blade edge is reduced by the flat surface 4, smoothness is enhanced and surface quality is improved, so that crack generation on the blade edge and tool abrasion are suppressed.

Abstract: In a bending type mechanical descaling method, streak-like scales remain, which cause a die seizure in the subsequent drawing process. In the present invention, there is provided a quite new mechanical descaling technique capable of eliminating such streak-like scales. The new mechanical descaling method includes the step of passing a metal wire through a torsion generating portion for forcibly turning the metal wire around the axial center thereof while running the metal wire, thereby removing scales due to a difference in toughness between the metal wire and scales.

Abstract: An ultrasonic flaw detetor for a wiredrawing apparatus, combined in a compact construction with the drawing die box and guide die box of a wiredrawing machine. The ultrasonic flaw detector comprises a cleaning tank disposed contiguously with and after the drawing box and provided with drain ports, a first partition disk having a hole for passing the drawn wire, an ultrasonic testing tank joined coaxilly to the partition disk and provided with a supply port for receiving an ultrasonic testing medium therein a second partition disk having a hole for passing the drawn wire, and a drain tank having a rear end attached to the second partition disk and a front end attached to the guide die box and provided with drain ports.