Internal Threading Vs. External Threading: Don’t get Screwed by Catchy Marketing Terms

“There’s no way I could be reacting badly to my jewelry. I paid a lot of money for this piece and my piercer promised it was totally safe!” Unfortunately, we see this same scenario unfold again and again. Something thought to be safe because it’s advertised or sold as “surgical” or “solid”, ends up containing sensitizers like nickel that cause irritation. So how do you, as a consumer, protect yourself from buying low quality jewelry? Well, there are a few different ways to tell what material a piece is made out of, but thread pattern is the number one dead giveaway for most. Thread pattern refers to the style of screw that’s used on the jewelry itself for assembly. An external thread is when the screw is on the outside of the barbell, and the ball has a hole in it that the bar then screws into. Internal threading is when the barbell has a hole in the end and the bead has a screw attached to it that screws down into to barbell. There are currently no American made body jewelry companies producing externally threaded jewelry out of body safe, high quality materials; which means, if it has external threading, there’s a good chance it’s a low quality material.
It’s important to note that there are high end companies that produce internally threaded pieces in materials like gold and implant grade steel (ASTM F138) that are safe for some to wear, but even implant grade steel contains trace amounts of nickel and unless it’s specified otherwise, so do the majority of gold alloys. For those who are very sensitive to to nickel, you may still react to those pieces. Also notable is the fact that there are low end companies who have started producing internally threaded mystery metal pieces, that despite their thread pattern, are not safe. This means that not every internally threaded piece is safe for everyone, and although thread pattern is a good starting distinguisher, it’s still always recommended to ask questions about what materials are being used and do your research before buying!
In recent years we have seen a rise in companies and studios lying to their clients about materials and threading. It’s unfortunate but it’s why we feel so strongly about educating others so no one gets taken advantage of. Essentially, If you see external threading, it’s easy to know that the jewelry is unsafe and to stay away. Now, how can you distinguish quality internal threading from bad internal threading? Good quality internally threaded jewelry should be made of implant grade materials. It should have a mirror polish on the barbell (meaning you should be able to see your reflection in the piece) and it shouldn’t have any knicks, scratches, or tool marks on the barbell or beads. Quality materials come with American mill certificates, that state that the material is implant grade titanium (ASTM-F136) or implant grade steel (ASTM F138) . Your piercer should have those certificates on hand and should be able to provide them as necessary. However, some jewelry companies have been caught fabricating these certificates, or getting them from countries with very lax standards; because of this, it’s best to stick with reputable brands and studios who you trust to be using the correct materials. Titanium can also be anodized, so if you’re ever unsure of whether something is titanium or not, try anodizing the jewelry which will confirm the material right away! Titanium and steel do however come in different grades, which is why we stress looking for implant grade above all. 
Aside from externally threaded jewelry being produced in lower quality materials, the style overall has presented many issues. With externally threaded jewelry, those coarse threads on the end of the barbell have to pass through your piercing when inserted and removed, which is not only extremely uncomfortable, but can also tear and damage the tissue around it. This damage can result in irritation even for healed piercings. Not to mention, these exposed threads can collect and trap bacteria as they pass through your piercing which then remains on the jewelry. External threads are often shorter and rougher which means the threading can easily come undone, or even get stuck together. In the state of Oregon they can’t even legally pierce you with externally threaded jewelry, thanks to extensive documentation that this style is harmful to your piercings and your health. Other cities and states are working on improving their laws in regards to what can and cannot be used for piercing as more and more information arises around quality materials and styles. Listed below are the regulations for body piercing in both Florida and Oregon: 
  • “331-900-0105
  • Initial Jewelry for Standard Body Piercing
  • A standard body piercer must meet the following jewelry grade standards for initial piercings unless requirements listed in subsection (5) of this rule are met. 
  • (D) All threaded or press-fit jewelry must have internal tapping (no threads on posts);
  • (E) For body jewelry purposes, surfaces and ends must be smooth, free of nicks, scratches, burrs, polishing compounds and metals must have a consistent mirror finish.
  • (2) A licensee must have a “Mill Test Certificate” for all jewelry used for initial piercings which provides evidence of a specific grade of metal with a code designation from the ASTM or ISO, which must be available on the facility premises.”
 
Internally threaded jewelry has no screw on any part of the piece that’s being worn in the body. This means the jewelry is completely smooth when it passes through your piercing. Internally threaded jewelry also has things like insertion tapers, that screw into the jewelry to allow for a comfortable insert and removal of the pieces. Internal threading also has something called a countersink. This is a little divot in the partnering beads that allow them to slide over the barbell and grip down onto the bar when tightened; making them much more secure! In the end, the preferable and safest option is the modern internally threaded style. 
Board of Electrologists and Body Art Practitioners Rules – OAR Chapter 331, Divisions 900-950