DO NOT buy these as sealing (crush) washers
I purchased these because I was building the brakes on my project car and figured I'd use these throughout as crush washers. BIG mistake! The quality is terrible - every washer has a little burr edge all the way around and not all are truly flat. I'm not sure what they're intended for but it's certainly not fluid sealing as crush washers. I ended up buying washers at 5x the cost at my local car store, but at least those worked for the application.I guess the moral is you get what you pay for. Cheap product, terrible quality. NOT recommended for automotive use.