These are excellent cutters and half the price from McMaster/Carr or similar industrial stores. You can cut many different materials. I've used them a lot on aluminum. They work great, but you'll need to use some A-9 aluminum cutting fluid or WD-40 or similar to keep the burr from getting aluminum filled. Some alloys are much worse for this than others, but once the burr is filled it will be almost impossible to clean it again. The thorn is of course not to blame!