Originally Posted by
repechage
My penatrant of choice for steel fasteners is Kroil
"don't spoil it, Kroil it"
for the hex head, grind back a 6 point socket to provide full engagement of the bolt head.
Ans yes, thin a a wide "minus" screwdriver and notch it.
+1 on grinding the socket down for flat, flush engagement, if purchase is poor, the results will also be.
