Originally bought for FXSB but went a different route. 1.25 inch diameter. Other dimensions in photo - new never unwrapped. Located in Brissie

TUSSUCK!!

Holey shit no!....  Im about curved and radiused bars not square monstrosities (plus they need a certificate for the welding)

Now where did I put that welding certificate

Yep...  Im putting solid slugs inside to avoid that issue.  The bars in the OP should be fine as I would assume they would have been manufactured to spec anyway.  Its just homemade ones that need to be thought through.

Who's engineering your bars?

No one.  I an tack welding and then getting a professional welder to do the actual welding.  Im am an okay welder but prefer a pro for the finish.  Plan B is to buy some Stainless Tube and then do it all as a single set of bends with no joint at the base curve and use some form of bastardised clamps.