Tap:
Helical Tap
Spiral flutes are commonly used in blind holes and when threads are required close to the bottom of the hole. They are available in many different helix options, which are chosen depending on the type of material being tapped.
Spiral flutes are commonly used in blind holes and when threads are required close to the bottom of the hole. They are available in many different helix options, which are chosen depending on the type of material being tapped.