You are correct in that intrinsic hardness is only about 40% of the equation (also 30% pressure, and 30% lateral force under pressure), and the ability to disperse said forces elsewhere than the pressing screen will REDUCE the scratching that occurs. But there are way too many reports of scratches on the screen for the issue to be so easily dismissed.Quote:
Originally Posted by giannib
dust & sand are not aproblem: watch the video with a key:
If you're confident in your knowledge that sand won't scratch the screen because a key won't, go ahead and test that for us. Maybe even put a recording up on YouTube.
But before you do that, you may wish to check this out:
Mohs scale of mineral hardness - Wikipedia, the free encyclopedia
Look at where quartz / SiO2 is on that scale. Compare that to the hardness of the metals used in keys.
Actually, please don't test it for us. You absolutely **will** scratch your screen with sand.
There's no need to use such sarcastic tone, I'm just losing time trying to help.
Answering to your opinion, using a grain of salt, let me note that such scale must be used in similar conditions, so a stone of comparable dimensions, or sand-paper.
Loose grains of sand have all degrees of freedom and will roll on the surface.
I don't need to test it, I did it, I spend half of the year lying on sand beaches, and never had any injuries.
Let's buy all the protection you want, but try not keep stones in your pocket.
Also, grains of salt ("Halite" @ 2 - 2.4 Mohs) are much less of a concern than grains of silica (@ 6.2+ Mohs)
Upvote
0