Screw-Hole-Related Tools
Threading tools have functions to cut threads in accordance with the required thread types and sizes, or to conduct plastic forming. Commonly-used tool type is formed tools called taps. They are used in many different ways; for example, handles are attached to them for manual machining, or for large-lot production, they are mounted to machine tools called tool holders or NC machine tool. High-speed steel is most commonly employed for these tools, and alloy carbide (coated alloy carbide is mainly applied) is also increasingly employed for its durability. When threading with taps, the thinner taps are, the more likely they break. As cutting chips solidify with heat, or the tap end makes contact with the bottom of pilot hole, there is more possibility the tap is damaged. Additionally, when using a coil insert, a dedicated tap needs to be used rather than a regular tap.