The raw material you are asking about is not really tubing or bar stock. Normally, the only way to procure mild steel material in this form is to have solid bar stock trepanned or have short lengths roll forged. You can have lengths of a foot or two roll forged. Or you can have lengths up to 10 or 15 feet trepanned.
We are making non-standard large nuts. I can use hex bar stock; final size OD; then bore, and tap to thread. Or I can use a hex OD with round ID tube in which case we final size OD; finish bore and tap to the thread.
The tubing will save considerably on machining costs if the dimensions are close enough.
who has the capability to perform this toll work? We are looking for MIll quantities 10-20K# I have also considered having heavy wall 5.5" tube rolled to the hex shape as long as reasonable tolerances can be held.
If you require short length rings of 5.5" OD x 3.5" ID, then purchasing roll forged rings might be a good option. The material can be roll forged into a thick walled tube to a length of around 6-8 times the OD, and then it can be parted off into the short length blanks you require. The nice thing about roll forged rings is that there is very little material scrap.
