What does 'internally-threaded' mean?
All 'screw type' body jewellery is manufactured using one of the following variations of threading: internal threading or external threading. Most standard body piercing jewellery is externally-threaded. The type of threading normally makes no difference whatsoever to the majority of people and, visually, you can't even tell which type of threading is used once the jewellery is fitted into place. Internally-threaded body jewellery is something which is normally asked for by choice. External threading (the most common type) means that the end of a bar has threading around it, whilst the separate ball contains a small hole with threading inside. The threaded bar is then screwed into the hole in the ball. On the other hand, internal threading means that the end of the bar has a hole inside it (with threading), whilst the separate ball has a small protruding stem with threading around it. This stem is screwed into the hole at the end of the main stem of the jewellery.