I am a marine mechanic and often have to drill large holes in thick steel on ships to run cables on board. I bought this item hoping it would perform better than the standard steel hole saws we all buy at Home Depot. Even if I can do without the plasma cutter, all the better - hot work on the boat is definitely out of the question! (no operator error). This hole saw had a tooth chipped, the center piece broke in half and IN FIVE SECONDS my hand slammed into the bulkhead. DO NOT BUY THIS ITEM!