Sulpher,
As far as circular saw blades, they're working well for me. Just shot one into a concrete block, from about 30 feet. It was on my first arrow. I hardened and tempered it to straw, so don't know how it would work, straight up. But it didn't break, or bend, and it went in about 3/8". Cut it out with a cut-off blade and pnuematic grinder. There's a pic of it, under 'very first arrow' on the first page of the thread, if you're interested. I'm a carpenter, so free blades, forever, for me.
dogleg