I've tried bits made from high speed steel, titanium, and cobalt. I've double and triple checked to be sure the drill is turning the correct direction. I haven't tried carbide because I don't have one. I see they around $20 for a 1/4" bit. I can barely scratch the ring with a file. I'll probably chuck it up in the lathe at work tomorrow and turn the ring down until it slides off. Hope they have some carbide cutting tools. I'll probably have to cut the old inner bearing race off too. I'm fairly sure the bearing and ring are original Volvo. I can heat the new bearing and ring with an induction bearing heater and hopefully get them on without to much hassle. Thanks to all for your feedback. jp