It depends on how thick of steel you're aiming to cut. But most job shops process steel with either laser cutting (for thin steel) or waterjet cutting (for up to 12" thick)... or machining. I'd look...
My favorite method is to cook steel cut oats in a slow cooker. Put 1 cup oats and 4 cups water in a slow cooker. Cook for 4 hours on low, or 8 hours on "keep warm" setting. When it's done, add around...
water can only cut through steel only if you get jet water! if you watched Richard Hammond's blast lab on the 8th of January 2010 it tells you that answer so that's how i know the answer.