Jewellery FAQ: Internally Threaded Jewellery: What is It and What is the Difference?

~PLEASE NOTE: All posts on my blog are meant as educational posts. They are not intended to shame or offend anyone who has purchased, used, or sold lesser quality jewellery, but rather share knowledge to help clients make an informed choice when deciding what jewellery is best for them. Some may have differing opinions on certain parts of the blog, however I write this having been educated both when I was an apprentice and through conferences and seminars over the course of my career, with only positive intentions and high standards in mind.~

Often I am asked why I only use internally threaded implant grade titanium jewellery and what the difference is between internally threaded and externally threaded.

Internally threaded means the screw thread is hidden inside the post. The sharp edged screw threads are hidden with internally threaded jewellery so they are more comfortable to insert and wear in a fresh or healed piercing. The post can easily slide in and out of the piercing without catching on and tearing the tissue which means that there is far less risk of damaging the piercing and causing inflammation or discomfort. Internally threaded jewellery also allows for lower profile designs such as bezel set discs as the bulky external thread doesn’t have to be hidden inside the threaded end. Additionally, this connection type is more secure than external due to the design which means less chance of losing jewellery.

The design of an externally threaded pierce of jewellery has the screw thread exposed on the outside of the post. The screw thread can cause damage and discomfort during insertion into a fresh or healed piercing and if any of the thread is exposed it can irritate the piercing channel by causing micro tears and cause excess scar tissue growth. Externally threaded jewellery is far cheaper to purchase than internally threaded jewellery and is far more difficult to find in certified implant safe materials or with a polish smooth enough for initial piercing. Additionally, the screw thread tends to get worn down during the machine polishing process which makes the threaded ends less secure than other connection methods. This means there is a higher chance of losing jewellery.

As I have mentioned in previous educational posts, always keep in mind that not all titanium is implant grade ASTM F-136 or ASTM F-1295 and a lot of industrial titanium is used by budget jewellery brands. Grades 5 and 23 are the most common low quality grades used. Industrial grades may be safe for wear but have not been proven to do so as they have been designed for other attributes and uses. A large percentage of externally threaded titanium jewellery is not implant grade, so make sure to always do your research before purchasing!