I use this for welding steel, stainless steel, titanium and aluminum. What I like the best about it is the high frequency control, from starting a weld on steel and the continuous high frequency for welding aluminum. Once I got it. The first thing I tried was to weld a old piece of aluminum that had paint on it as well as being very dirty. I have to say I was very impressed with the quality of weld it put down. Can't wait to build something really cool with it! The down side of it is, the fan is very loud on the welder and the cooler when they come on. And I wish it came with at least a 25 foot power cord instead of the 10 foot.