LOL, well yes it is a alloy bolt and yes it is heat treated. Alloy steals come in many different types its dependent on the amount of iron and carbon and the grade of the bolt refers to the hardness (heat treating process) so yes they are heat treated alloy bolts. Its the highest grade metric bolt (grade 12 for metric) I doubt that i will have a problem with the damn bolt. I can see and under stand your point with the manifold, but the bolt is under little strain and im pretty sure that it is made out A2 tool steel which most high grad bolts are and if you look up the uses from that type of steel you will see that they use if for stuff that takes more abuse then a bolt mounting a 02 housing on a turbo.