Viking Type 721 Plug Chamfer Hand Taps are manufactured of High Carbon Steel with a plain finish. The Plug Tap chamfer style is the most popular and versatile of the 3 common styles of hand taps. They can be used for creating new threads or chasing damaged and rusted threads. The first 3 to 5 threads of a Plug tap are chamfered. This allows the user to begin creating new threads nearly as easily as when using a Taper tap with the additional benefit of having more complete threads available for carrying a useable thread closer to the bottom of a blind hole. The progressively chamfered threads of a Plug tap reduce the effort necessary to create new threads by progressively increasing the amount of material being removed by the tap. Plug taps may be used in both blind or through hole tapping. For tapping operations that require a complete thread to the bottom of a blind hole a Bottom tap will be required. Bottom taps are often used as a secondary operation after using a Taper or Plug tap to begin the threading process. Viking Type 721 Plug Taps are an economical yet high quality tap series ideal for a wide range of Automotive and Shop hand tapping applications. Made in America of High Carbon Steel.