It stopped working after 3 uses on thin metal. The amp reader has moved from the 22-40 amp range to 0-16, does not work when the button is pressed, no air flows through. I called their support and they told me to send an email. I emailed them my problem and then they told me in my email that they would escalate it to Amazon customer service since I bought it through Amazon. I've had it less than 60 days and if that's how they treat their customers I'll stop spending money on it. No attempt to diagnose/fix the problem. Put the blame on someone else.