Abstract: Machining techniques and machining apparatus are provided for treating workpieces in an efficient and reliable manner. The machining techniques and machining apparatus employ multiple thread whirling heads associated with a single machining assembly, such that each of the thread whirling heads is able to act on a workpiece during a single, uninterrupted machining process. Screw threads may be formed that include first and second thread profiles and an intermediate transition region. The machining apparatus generally includes a processor that is programmed to control operation of the multiple thread whirling heads in a sequential manner.