I also encountered this problem. Then I put forward a plan, unscrewing the pipe and adding a mandrel in the middle to fit the inner hole slightly loosely. The outer ring is clamped by oil pressure, and then a chuck rotates, just like twisting a towel. Of course, it was aimed at tubules. I think it's worth a try as long as the clamping mouth is strong enough and the rotating torque is large enough. The customer's pipe is sawed by a sawing machine and needs to be chamfered at the flat end, so it can be chamfered at the flat end. However, the company has not approved my plan. If anyone thinks it's feasible, I'm willing to discuss it with you.