These power auger bits are designed for heavy duty professional use. 
They feature single twist with single cutter and side line medium screw 
point, and combination hex - round shanks. This type shank allows the 
bit to be used in various applications. Their design facilitates fast wood 
drilling by the use of machine ground hollows and a deep throat for 
fast chip removal. Heat treated tool steel for strength and long life.  
The 18" length bits have a flute length of 14",  the 8" bits have a flute 
length of 6".