In Reply to: CYLINDER HEAD STUDS, HEX NUTS & HEX BOLTS posted by Tim Daley(MI) on September 07, 2018 at 17:57:42:
It may be a good tip for some that the main reason the torque is less for the cylinder head nuts than for head bolts is that the nuts are fine-threaded. The same clamping force is achieved with much less torque when fasteners are fine-threaded. Over-torquing those fine-threaded cylinder head nuts is very bad. Substituting non-original hardware may result in having coarse threads on both ends of the studs. In that case, the torque for coarse-threaded cylinder head nuts would be the same as for bolts.
I found a solution for the occasional special 11/16" hex head nut needed to make a full set. I bought several scrap random lengths of 11/16" hex steel bar. Cut off a little fatter than needed, grind until it's the right size/shape, center bore, and tap for whatever thread is needed. Of course with my small lathe it is much easier to drill and tap an inch or two, then machine off as many as needed with that thread. On the lathe, it's not too hard to get the chamfers to look exactly like the original hardware. This works for ungraded hardware. I don't have any way to accurately heat treat, so I won't be making any cylinder head nuts.