I use my dremel alot. Those cut off wheels break so easy and the reinforced ones are so spendy. If you take one of the really thin disks for a 4" angle grinder (a worn out one is perfect) and break it into 4 pieces. You can poke/drill a little hole in the middle of each piece. Put on long sleeves and good safety glasses. Put the odd shaped piece in the dremel and grind on a thick piece of steel for 30 secs or so and it will round it right out. If you know a welder you can get a good supply of the 4" wornout disks free. They very durable. I think they work better than the dremel branded ones.