Replacment for the bolt that holds the tubing in place on my bender

[GRMhick]

My mtech bender uses a 3/4" bolt to hold the tubing in place when you are bending, and I would like to somehow attach a piece of 2.25" x.250 tube cut in half to clamp it in place instead. That way it won't dimple the tube. Any ideas on a way to attach it so the bolt can be removed, and the piece of 2.25" can spin around on the end of the bolt?

[Rock Ape]

How tight are you tightening it? I have similar bender and the bolt is to keep the tube from sliding on the die and to center the tube in the die.I just snug mine up and have never dimpled a tube.But if you want to build a clamp setup why not weld the piece of 2.25 .250 tubing to the buttom of a c clamp and clamp it across the die then you could eliminate the u shaped piece also?