Originally Posted by
Kuromori
Butted tubes are annealed several times in the butting process, there's a limit to how much cold working a tube can take, as cold work results in work hardening, so Reynolds selects particularly ductile grades of steel for butted tubes.
Thanks for the correction. I'm not sure if Reynolds do anneal between butting passes but I thought the whole thing was cold right from when it was a billet. But I have looked it up and there is some annealing between passes when making cold drawn seamless.
I think Reynolds probably buy cold drawn seamless blanks and then butt them in their facility in Birmingham. Since they are only changing the diameter by a few tenths of a mm I don't think they do any more annealing of their own. But I'll see if I can find out more definitively.