Review on DelitonGude Cobalt Suitable Steels Stainless by Patrick Reynolds

These are cheap bits that aren't sharp enough to cut through the steel material I'm working with. I've used other beats with much better luck. I use 3.5mm a lot more than the other sizes so I decided to try them as the price was reasonable. They leave almost no dents on the steel. It was worth trying, but it was one of those money-saving efforts that ended up costing more.