... many years. Including of tapered button bit, retract button bit, thread button bit. With ISO certificate & quality control. Button bits with 6tips, 7tips ... button bitTapered button bit(28mm, 30mm, 32mm, 33mm, 34mm, 36mm, 38mm, 40mm, 42mm, 44mm and so on. With different degree taper) Tapered ... , 22mm; Shank hex. 19mm, 22mm) B. Thread Button BitThread button bit (33mm, 35mm, 45mm, 51mm, 57mm, 64mm, 70mm ...