This wood drilling bit set is made of carbon steel and has a ¼ inch diameter shank. It includes sizes ⅝ inch, ¾ inch, 1 inch This wood drilling bit set has a bright (uncoated) finish, and has fractional inch measurements. It has a six-inch length. Plus it has regular spiral flutes, a straight shank, a right hand cutting direction, and a full-cone threaded tip drill point.