Was going to post a new thread on using a new tool for myself but, I found this thread and eesakiwi already mentioned it. I wanted to affirm what eesakiwi said about the garden loppers. They are great for cutting copper tubing (1/2"-3/4") and for many other things. I recently used them to cut off the aluminum and brass golf club ends. Its a great tool. Here is a link for them at HD:
Fiskars PowerGear Titanium 32 in. Bypass Lopper-398542-1001 at The Home Depot