Plug chamfers are the most commonly used chamfer and are designed for efficiently threading through and blind holes. They have 3 to 5 threads. Spiral point taps are used for tapping through holes. They have a flute geometry that shoots chips ahead of the cutting action to reduce loading and clogging within the flute.
Oxide, also known as black oxide or steam oxide, is a surface treatment that prevents chip building, galling and welding on the workpiece. It is commonly used on low carbons, stainless steel and ferrous metals. Vanadium High Speed Steel (HSSE) is made of high speed steel, carbon, vanadium carbide and other alloys to increase abrasive wear resistance and toughness. It is commonly used on stainless steels and high silicon aluminums.