I've used these pliers a couple of times to punch holes in a sheet of copper. They did a good job punching the holes, no problem with that. I then lent them to a friend to do the same. The spring that causes the handles to return to the neutral position popped out while she was using them. You can continue to use the device, but you must manually retract the handles to the open position before punching another hole. I ordered another set to see if it was just bad pliers or if they really are a piece of junk that won't last more than a few uses. They're relatively cheap, so I hope this won't be the last.