I actually bought these to top up my total order for free shipping but. Ten packs of earplugs is less than one brand of earplugs? Of course why not. A month later I ran out of inserts due to urgent work so I opened the package and placed one on the tool holder. The job was 2" mild steel, cut very well, and did the whole job with a single cutting surface. I've since used it on other steel, aluminum (kind of a rough finish, but still works) and even trim, and cutting some stainless steel parts.