I was hesitant to order this hole saw as reviews have stated that it has incorrect threads and therefore tends to unscrew the shaft. But I took the risk and have no regrets. I first tightened the saw on the shaft with a pipe wrench and made sure it was good and secure. I had no problems with that at all. It works exactly as it should and I suspect there would be no negative feedback if users took the time to properly tighten the saw.