What grade titanium should be used for body piercing jewellery?
THIS WILL BLOW YOUR MIND
What is the difference between ASTM-F136, Grade 23 (G23), Grade 5 (G5), Implant-grade, and Medical-grade titanium?
Which one of the following should we use for professional body piercing jewellery.
- ASTM F136
- G23 (Grade 23)
- Grade 5
- Implant Grade Titanium
- Medical Grade Titanium
One of the main arguments (discussions) we usually hear regarding titanium grades and quality is "What grade titanium should be used for body piercing jewellery?"
Just take a quick look on any body piercing forum and you'll see this question repeated over and over again. Fortunately there are a many number of people willing to impose their knowledge on this topic. Some are right and some are not. So let's try and seperate fact from opinion.
Take a look at the above list of titanium names we found bouncing around the forums and facebook piercing pages. There's quite a few. But which one should we be using?
I'm going to unearth the facts around these titanium names to try and find some answers.
One of the main terms we see is "medical grade" or "implant grade" titanium. So It's probably a good idea to research the medical profession first to see what grade titanium they are using and why.
Ever heard of AZoM? Nope, neither had I. According to AZoM.com, "AZoM is the leading online publication for the Materials Science community".
This sounds like a good place to start. On their website they state:
"AZoM educates and informs a worldwide audience of researchers, engineers and scientists with the latest industry news, information and insights from the Materials Science industry."
A bold an impressive statement I must say. So I took a look around their website and found a great article called "Grade 23 Ti 6Al 4V ELI Alloy"
Strangely though, I read not so long back (on yet another facebook piercing page) that Grade 23 is not suitable for body piercing. Maybe AZoM can shed some light.
In their article they state that "Titanium alloys are divided into three main groups: alpha-phase, beta-phase, and alpha-beta-phase. Grade 23 Ti 6Al 4V ELI alloy is an alpha-beta wrought alloy. The ELI stands for extra low interstitial".
Fair enough... But it doesn't answer our question does it. What I really want to know is, what is considered as medical grade titanium? Surely if it's good enough for a surgical implant, it will be good enough for a body piercing. Right?
So, I continued my research and came across Harrold Pihl, specialists in alloy and titanium since 1912 located in Sweden. They state that "Medical grade titanium has a code of Ti-6Al-4V ELI". Source here
Hold on.... AZoM just mentioned Ti-6Al-4V ELI in the same sentence as Grade 23. Yet on the piercing forums it's said that G23 isn't good enough for body piercing, however the alloy professionals say Ti-6Al-4V ELI is medical grade. Intriguing...
Harrold Pihl goes on to say "Titanium Grade 23 is very similar to Grade 5 except that Grade 23 has less oxygen, nitrogen and iron. This makes the alloy more ductility and better fracture resistance (but slightly less strength) than Grade 5 Titanium. Grade 23 is used, in chemical processes, medical applications and in the aerospace industry"
Interesting they both refer to G23 and Ti-6Al-4V ELI as the same thing. But it has a wide variety of uses I can see. Is there more evidence which should be used as a medical implant?
Then I came across a book written by Wilson Wang and Chye Khoon Poh (edited by Jan Sieniawski and Waldemar Ziaja) entitled "Titanium Alloys in Orthopaedics"
It's fair to say, there are a lot of big words in there that I don't quite understand. However I did find a conclusion, as follows "Ti-6Al-4V and commercial purity Ti are currently the most popular materials for implantation purposes" Source here
Also, I found Andrew Slanker from Kodak. He cited "United Titanium" as a go to reference. So I checked it out. It clearly shows on their table that G23 and Ti-6Al-4V ELI are the same thing. You can view more here
I know feel confident knowing Ti 6Al 4V is the medical grade titanium everyone keeps dicussing.
At this point I know what you're probably thinking.
- What about ASTM F136? (Because thats the best)
We all know ASTM F136 Certified titanium is the best for body piercing don't we.
So why hasn't it been quoted yet by any medical professionals?
Yep, you guessed it, I headed over the the ASTM website. And on there I found their F136 certification.
Standard Specification for Wrought Titanium-6Aluminum-4Vanadium ELI (Extra Low Interstitial) Alloy for Surgical Implant Applications (UNS R56401)
Yes, you read it right. Even I had to read it twice.
Titanium 6Aluminium-4Vanadium ELI (Extra Low Interstitial) or Ti-6Al-4V ELI for short.
It's true. Check it out for yourself here
So dispite all the forums arguing the difference between ASTM F136, G23 & Ti 6Ai 4V ELI, it turns out they are all exactly the same titanium and are suitable for implant into the body. AMAZING!!!!
It turns out ASTM isn't a grade of titanium. It is in fact a testing system to determine if the metal is Ti 6Ai 4V ELI.
At this point you could run off and tell your friends and clients about your findings and I wouldn't blame you. Everything in me told me thats what I should have done. However, I was invested in this revelation now.
I wanted to know about the ELI part.
Does the lack or ELI make the titanium not suitable for body piercing?
What is the difference between Ti 6Ai 4V ELI and Ti 6Ai 4V?
According to Mohammad Yousefieh of Semnan University.
"Ti6Al4V ELI (Grade 23) is very similar to Ti6Al4V (Grade 5), except that Ti6Al4V ELI contains reduced levels of oxygen, nitrogen, carbon and iron. ELI is short for “Extra Low Interstitials”, and these lower interstitials provide improved ductility and better fracture toughness for the Ti6Al4V ELI material."
Ductility "ductility, Capacity of a material to deform permanently (e.g., stretch, bend, or spread) in response to stress. Most common steels, for example, are quite ductile and hence can accommodate local stress concentrations."
Simple terms - It's slightly flexible. Which is great should it be fused to something such as bone tissue.
Fracture Toughness "“Fracture toughness” describes the resistance of brittle materials to the propagation of flaws under an applied stress, and it assumes that the longer the flaw, the lower is the stress needed to cause fracture. The ability of a flaw to cause fracture depends on the fracture toughness of the material."
Simple terms - It could break if there are flaws present and put under stress.
My take away from this was, they are essentially the same. One is slightly flexible when put under pressure and one will break when put under pressure if there is a flaw in it. How much pressure gets put on a piece of piercing jewellery compared to an aircraft or a hip replacement? Truth is, I don't know. But my guess is - a lot less!
Interestingly though I did find a quote suggesting Ti6Al4V ELI is more than likely used for medical implantation (depending on the implant) due to the small risk of breakage Ti6Al4V poses when put under imense pressure. Chemically they are the same but the medical cost of replacing such an implant when in a human body would not be ideal. So it is chosen more to eliminate financial loss should such an occurance happen rather than any medical reason. I'm not quoting this source for obvious reasons.
- Ti 6Ai 4V ELI & Ti 6Ai 4V is the medical grade titanium
- Also known as G23 or Grade 23
- ASTM F136 Is a certificate of examination and confirmation (others exsist)
If you made it this far i'd like to say thank you for taking the time out of your day. I'm really quite pleased with my findings. I hope you enjoyed it.
In my mind, fact always trumps opinion.