These Japanese pattern augers have a deep, high ratio flute, which quickly removes the waste chippings from the mortise. They have a conical point on the end and one cutting spur, which is very easy to sharpen with a small file. The flutes are also painted in a blue, low friction finish, which prevents waste chippings from adhering to the bit. There are approximately 20 machining operations involved in the manufacture of each bit. After every stage, the auger bits are visually inspected and rejected if they are not within tolerance. They are made from hardened (RC64) tool steel and are available in a range of imperial or metric sizes. The auger shank is not hardened and may need to be cut to length (to suit the machine) with a good quality hacksaw blade. These auger bits are supplied in a convenient storage tube.