Disassembling the front suspension components for axle cv boot replacement:
The pinch bolt (wheel bearing hub to upper control arms) got broken (despite days of penetrating oils soaking).

Does anybody know what material (alloy) is the bolt made from? (Does not seem to be from steel).

Heating the housing did not help so far

Is the drilling the only option to get the bolt out?

 

if you do need to drill, use left handed drill bit's, alot of time the bit will grab and pull out the bolt. For this to work you need a stout drill!! No cheap battery operated drill.

 

either a left handed drill bit as stated before would work, or an "easy-out" (its kinda a square rod with a hex bit on the end of it if you've never seen one) works real well sometimes. you just need to drill a small hole then hammer it into the hole you made(you need a good hammer) and with a bit of luck you can unscrew the bolt like that, but if you have bad luck the easyout will just round out the hole you hammered it into, or worse the easyout can break inside the hole... you do not want to have to drill out that metal on the easyout...

 

if you use an "easy out" make sure to apply constant steady pressure. th easy out id made of much harder metal then the bolt, and their a pian to drill out if one breaks. When i use one i get my T-handle on, then a breaker bar and slowly add pressure untill the bolt comes lose.