Walter-Prototyp - Spiral Point STI Taps Thread Size (Inch): #2-56 Class of Fit: 3B

Plug chamfers are the most commonly used chamfer and are designed for efficiently threading through and blind holes. They have 3 to 5 threads.

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.