How to Tell If Your Glasses Are Made of Pure Titanium: A Simple Guide

When we talk about pure titanium, we're referring to titanium metal with a purity level of at least 89%. However, there’s a common misconception that pure titanium must be 100% pure, which is incorrect. Since its introduction, pure titanium glasses have been popular due to their lightweight, corrosion resistance, high melting point, strong stability, and biocompatibility, making them a favorite choice for those seeking prescription eyewear.

However, because titanium's elasticity and weldability are not as strong as some other materials, many manufacturers add other metals like aluminum, vanadium, and molybdenum to create titanium alloys. Unfortunately, some eyewear sellers, taking advantage of consumer knowledge gaps, may pass off titanium alloy frames as pure titanium, in order to profit.

The Price Difference

Pure titanium frames are much more expensive than titanium alloy frames. To protect yourself from dishonest sellers who might pass off titanium alloy as pure titanium, here are some simple ways to distinguish the two:

Method 1: Weighing the Frame

Titanium alloy typically has a density of about 8.9g/cm³, while pure titanium has a density of just 4.5g/cm³. Since titanium is much lighter, pure titanium frames will feel noticeably lighter than titanium alloy ones. This is one of the easiest ways to differentiate between the two.

Method 2: Inspecting the Welding of the Nose Pads and Bridges

Pure titanium frames are welded using an oxygen-free butt-welding process, leaving a "step" shaped weld mark. On the other hand, titanium alloy frames are typically spot-welded, creating a "slope" or "ramp" shaped mark. This is an effective way to tell if the frame is made of pure titanium or not.

Method 3: Checking the Hinges for Spacer Plates

Pure titanium frames do not allow the titanium to directly touch other titanium parts at the hinge, as this can cause the joints to wrinkle or become stiff. Typically, pure titanium frames use small spacer plates at the hinges to keep the top and bottom hinge parts separate. If you see these thin plates at the hinge, it’s a good sign that the frame is made of pure titanium.

Method 4: Magnetic Test

Loosen the hinge of the frame and use a magnet to test its magnetic properties. If the legs of the frame are attracted to the magnet, then the frame is likely not made of pure titanium, as titanium is not magnetic. If the frame doesn’t respond to the magnet, it may be made of pure titanium.

By following these simple methods, you can avoid being misled when purchasing your next pair of glasses and ensure you're getting what you pay for. Whether you're looking for the lightweight comfort and durability of pure titanium or simply want to know the true material of your eyewear, these tips will help you make an informed decision.