I had the same problem, broken 8″ blades on a strikemaster mora hand auger that is being used with the Clam adapter plate and a Milwaukee 18v Fuel drill. I think the problem may be that the blades leave a partial lip of ice at the bottom of the hole when they punch through. Then when you pull the auger up out of the hole the blades, which stick out past the auger fins, slam against the lip of ice and eventually break off at the weak point, the bolt hole. I dropped down to 7″ blades and don’t think I’ll have this problem again, as the auger cleans up the bottom of the hole when it punches through. It’s also a bit easier on my Milwaukee drill. Sure, a smaller hole but I saw a video of a guy pulling a 15″ crappie up through a 5″ hole – obviously a tight fit but he got it done. So I think a 7″ hole will do me just fine unless I run into that new state record, lol!