I bought one when they first came out. It was rated for a higher guage then, and I broke teeth on 18g SS (300 series, which are all about the same), and had problems feeding .100 aluminum shield material. Instead of feeding, it would make little slivers. The teeth (upper wheel AIR) will leave marks on the side it is on. It didn't come with instructions, so maybe it wasn't adjusted right. I thought it would work like a beverly, but somewhat "self feeding", but it didn't work well in my experience. For 18 mild? Maybe it would be worth it. I paid $429 for mine, and it is sitting on a shelf.