These Screw Machine, or Stub, Length drill bits are designed for applications where increased hole accuracy and extended tool life is required. This is achieved by the shorter length as compared to other drill bits which provides maximum rigidity.

Double margin drill bits have an additional margin ground behind the leading margin, providing twice the number of contact points. This second margin performs various functions to improve hole quality. The trailing margin burnishes the cavity, making a true hole and smoother finish, helping to provide a more concentric drilled hole.