In answer to some query within the last two weeks, I mentioned a harbor freight metal cutting circular saw - it's on sale in the current catalog, for $75, log number 8897, blades are $17 - it's on pg 19 of catalog 14b-1 . I've used this on automotive sheet metal, and on I beam material that was
1/2 to 3/8 thick, no problem, even cutting the I part where it was cutting through about 3 inches at once. I like this a lot better than an abrasive saw.