[potato3732842]

The QA in this case is that the welder knows he doesn't suck and he knows when he does a good job. A 3/4 or so (approx the size most steering stuff is) shaft is going to be more than capable of handling steering wheel torque

Not everything needs to be treated like a nuclear reactor.

[binoct]

Luckily welders do not suffer from superiority bias.

[potato3732842]

With a competent welder it's basically never a question of whether or not the weld was good. It's a question of what's sufficient for the application. If you care enough you can make perfection happen but caring that much on everything is time consuming and unnecessary.

X-ray and other inspection processes are mostly there to force people to behave like they give a crap.