"Titanium" on a product page can mean several different metals, and they are not interchangeable. Some are pure titanium, some are an alloy, and some listings use trade shorthand that tells you nothing about the grade. This guide explains what G23 means, how it relates to ASTM F136, and what to look for when a listing only says "titanium".
What G23 refers to
G23 is a designation from the Chinese titanium standard (GB/T 13810) for Ti-6Al-4V ELI: a titanium alloy with 6% aluminium, 4% vanadium, and extra-low interstitial elements such as oxygen and iron. The "ELI" part is the one that matters. It means the alloy has tighter limits on those trace elements, which makes it more ductile and better suited to body jewellery than the standard-grade version of the same alloy.
The international equivalent is ASTM F136, the specification most piercing studios and jewellery brands quote. When a listing says "G23" or "ASTM F136", both are pointing at the same family of alloy, just under different standards.
G23 alloy vs commercially pure titanium
| G23 / Ti-6Al-4V ELI (ASTM F136) | Commercially pure (Grade 1–4) | |
|---|---|---|
| Composition | Titanium with 6% Al, 4% V | Titanium with trace oxygen only |
| Strength | Higher, holds fine detail and threads well | Lower, bends and deforms more easily |
| Typical use | Piercing jewellery, threaded ends, hinged rings | Industrial, some basic body jewellery |
| Colour options | PVD coating for gold-tone, anodising for colour | Anodising only |
| Cost | Higher | Lower |
Pure titanium is not "worse" in every way: it is lighter and very corrosion resistant. But it does not hold a fine thread or a hinge as well, and a detailed front end made from it tends to wear faster. That is why most implant-grade piercing jewellery, especially anything with a hinge or a screw thread, is made from the ELI alloy.
What the grade does not tell you
The alloy is only half the story. Two pieces can be made from the same G23 bar and feel completely different depending on the finish:
- Polished surfaces are smoother against the skin and easier to clean.
- PVD coating gives gold-tone colour. It is a coating, not solid gold, and it can wear at contact points over time.
- Thread quality decides whether a top screws on cleanly for years or cross-threads in a month.
None of this shows up in the grade name. It is the reason we list finishes separately from material on every product page.
How to read a titanium listing
- Look for a grade or a standard, not just the word "titanium". "G23", "Ti-6Al-4V ELI" or "ASTM F136" are specific. "Surgical titanium" is not a grade.
- Check whether the colour is plated. If it is gold-coloured and priced like titanium, it is PVD-coated. Solid gold would be priced very differently.
- Check gauge and dimensions on the size diagram. A correct grade in the wrong size is still the wrong jewellery.
- Ask what the thread is. Internal thread (the top carries the post) is more common in quality pieces because the threaded part sits inside the bar, away from the piercing channel.
Does grade matter for sensitive skin?
Grade matters more than marketing language. Titanium is chosen for piercings because it is light and resists corrosion, and the ELI alloy is the version specified for implant use. If you have reacted to other metals, the grade and the finish are the two things worth confirming before you buy, not the colour of the box.
We list the material and finish on every product page, and each one includes a size diagram. You can browse the current titanium hinged ring collection or the new arrivals to see how the specifications are presented.
Summary
G23 is the ELI titanium alloy under the Chinese standard, and ASTM F136 is its international counterpart. It is stronger and holds detail and threads better than commercially pure titanium, which is why it dominates implant-grade piercing jewellery. What the grade will not tell you is the finish, the thread quality or the size, so read those separately. For sizing, see the piercing guides index, or browse flat back labret studs and septum clickers.