Originally Posted by Dirtdrop
Is that supposed to be a response to what I posted?
In one sentence he says that it's impossible to split a crank by over tightening the bolt. He contradicts himself in the other sentence.
Not all in one go. The bolt isn't splitting the crank per se - what's happening is that the bolt snugs the crank up, then the crank settles because of all the torque of riding on it. You repeat that several times and the process can lead to stress buildup that fosters a crack and you're done.
So basically: bolt all by itself won't split a crank because the threads aren't that strong.
Pedaling all by itself won't split a crank (for a few tens of thousands of miles) because you aren't that strong.
Chasing a crank with a bolt, then pedaling, then chasing, etc, can strain the crank by degrees until it fails.