Frame Materials of Eyeglasses
With the development of technology, there are more and more glasses frame materials for eyeglasses, and today I will mainly introduce three common eyeglass frames materials which are aluminum, titanium glasses and steel.
Before you will really know what are aluminum frames, titanium frames and steel frames. You should know the concepts of stiffness, strength and weight first.
Imagine you clamp one end of a metal bar in a vise, and you hang a weight on the free end, causing the bar to flex temporarily. When you remove the weight, the bar snaps back to its original shape.
Different materials will flex different amounts for the same amount of force applied. This is stiffness also modulus.
Now imagine hanging a heavier weight on the bar, so heavy that it becomes permanently deformed. When you remove this weight, the bar does not snap back all the way to its original shape, but remains bent to some extent. When the metal changes shape permanently, it is said to “yield.”
Different materials can withstand different amounts of force before yielding. This property is strength.
In addition to the strength and stiffness, there’s also the question of how heavy a given volume of the material is. This is called weight also “specific gravity.”
Like stiffness, the specific gravity of a given metal is not significantly affected by the addition of different alloying elements, which means that all steel is equally heavy.
Then you should know some facts. The modulus of aluminum, steel and titanium are 10-11, 30 and 15-6.5. The yield points of them are 11-59(4-22 annealed), 46-162 and 40-120. The specific gravity of them is 168.5, 490 and 280.
The identical steel and titanium frames will be about equal in strength. However, the titanium frame will be about half the weight and half stiffness. So such a titanium frame would likely have a whippy feel due to the reduced stiffness. To compensate, builders of titanium frames use somewhat larger diameter tubes to bring the stiffness more into line with what riders like. This tends to increase the weight a bit, but by making the walls of the larger tubes a bit thinner, they can compensate to some extent, and come up with a frame that is still lighter than a normal steel frame.
The situation with aluminum is even more pronounced. The “identical” aluminum frame would be 1/3 as stiff as steel, roughly half as strong, and 1/3 the weight. Such a frame would be quite unsatisfactory. That’s why aluminum frames generally have noticeably larger tubing diameters and thicker-walled tubing. This generally results with frames of quite adequate stiffness, still lighter than comparable steel ones.
Therefore, anyone who tells you that a particular brand of steel (or aluminum, or titanium) is “lighter” or “stiffer” than another brand or model is blowing smoke. You should choose your frames according to your own condition. If you are unable to handle this thing, you can go to some online glass stores, such as www.visionsking.com, for advice.In VK,you can buy reading glasses,prescription glasses and cheap glasses!
      
      
     
    
