Uxcell 2Pcs Round Threading Dies, Metric M4 X 0.7 Thread (Right Hand), Round Threading Die: Thread size: M4 x 0.7 (right hand); outside diameter: 25mm / 0.98"; thickness: 9mm / 0.35"; accuracy class: 6g. Made of M2 (6542) high-speed steel, it has high hardness, good toughness, wear resistance, and excellent cutting performance. Wide Applications: Round dies can process, correct or clean the external threads, and is used for ordinary thread processing of stainless steel, aluminum alloy, cast iron, copper, iron, aluminum, plastic. Great for maintenance and repair work on pipes, boards and machinery. Features: Conical locking hole, strong locking force, no loosening. Suitable for re-threading existing threads in hard materials like metal and making new threads in soft material such as plastic. The surface is lubricated with grease to prevent rust, the thread is clear and easy to repair. Easy to Use: Threading die is used with die stock (also called die handle or die wrench). The positioning groove of the die should be aligned with the fastening screw in the middle of the wrench, and the screw should be inserted into the groove of the die and tightened. It needs to be reversed every 1/4~1/2 turn to facilitate the chip discharge from the chip hole. Tips: Suitable lubricating oil should be added to the cutting edge of the die when tapping the thread. The end of the bar stock should be chamfered 1*45 degree, and the chamfer is too large to cut in. The bar diameter should be smaller ( about 0.05mm-0.15mm) than the nominal diameter of the required thread.