I just bought a Hyper Therm 600 and it will cut 1/2" does a great job on 3/8". Don't buy one that will just barely cut the size you need. Buy one that is a little bit better because of the duty cycle thing.

before you buy look at Ebay there are some great deals on there with no shipping. I called Hyper Therm to check before I bought from a dealer on Ebay. Hyper Therm said they buy in large quanitys to get a good price and pass on the savings.