The burnishing drill has four margins which stabilize it as it is drilling.
The two extra "Burnishing" margins also help to smooth the hole after the "Cutting" margin has cut, giving the hole a better finish than a conventional drill. They also help to make a hole that is consistent from one to another. Because the burnishing margin actually moves material back, it is essential the burnishing drill be first made of carbide, which has the compression strength and then only of the highest quality.
The straight flute construction helps to break up the chip into a smaller, more manageable size.
The rigid construction allows the burnishing drill to drill a straighter and less oversized hole than a conventional twist drill.
Although we do not advertise it, one further benefit of the burnishing drill is extended tool life, many times giving the customer 3-4 times the tool life of conventional carbide twist drills, solid carbide three flute and even subland drills.