Originally Posted by
Torchy McFlux
12.9 steel is great for everything bike-related. I'm not a fan of stainless because it is weaker, and while titanium is high-zoot, it's unreasonably expensive and on the delicate side for my taste.
I can't think of a bicycle application where the standard Grade 2 steel or typical stainless steel bolt wouldn't be more than strong enough. Possibly square taper crank fixing bolts justify a higher strength rating but nothing else. As Crankycrank noted, the threads in the Al wedge will fail long before the bolt breaks.