InlinePRO M12 Extreme Duty Head Studs - 00-09 S2000 F20C F22C - HSK-S2000Our S2000 F20 22C M12 Extreme Duty head studs are made from the highest quality American steel that have gone through rigorous testing and treatment. These are not prone to hydrogen embrittlement like the L19 H11 material and it can be handled without worrying about failures. It will handle 80 pounds of boost making 1800 2000hp. We use a true beam design all the way through the length of the stud (it's not necked down or undercut like others)