Hello Shay, for my application at least one sufaces must be polished, the other one can be etched. I can realize such crystals with pure chemical wet etching methods, so crystal quality in the edge will be perfect. Do you have any reference for the cited values ? Many thanks, Andrea On Dom, 20 Aprile 2008 3:24 pm, shay kaplan wrote: > Andrea > This is very tricky. You bet numbers from 0.5 to 30 GP. It is very > dependent > on the surface and edge quality of the structure you will test. Usually, > the > smaller the structure, the stronger it is because it has less defects. > > Best shay >