To be honest, I don't know if my glass is float or plate. I just went in and asked them to cut me a piece of 3/8 thick to my dimensions. I wonder if the difference would be significant in the distance over which we use it, and the way we use it? I do know that the glass I got works plenty good for my sharpening. I've put plenty of elbow grease into my glass when tuning a slick. No problem. I have the glass supported by an MDF frame/board, and this sets on my steel workbench. So long as your frame is on a reasonably flat surface, I think you'd be fine. Not you'd have this issue, but the glass does have a little flex to it before it would break, and I think the thicker you go, the stronger it will be. You could step up to 1/2 inch, but more than that is probably more than is necessary.
