Best bolt grade for Triumphs

[trfourtune]

the reason why some say it is ok to use one grade lower nuts than the bolts, is so that any failure is in the nut, not the bolt.the bolt is what stretches which give the pressure(consistent torque value).if you re-use the bolt on a non critical component,you keep the bolt and toss the nut for a new one (where dismantalling)because if there is any thread failure (not visible) it will be in the nut.lower grade nuts are less money, nuts are less money than bolts.
personally if i use a gr.8 bolt i use gr.8 nut (usually this is a safety factor thing)i re-use both because i am still cheap but i hate broken bolts and threads that strip.we usually do not tighten items up to the yeild.
ps-seat mounting bolts and seat belt bolts are a critical item.i had the seats in my old turd-cell (tercel)rip out from being hit from behind. we ended up in the back seat whith the back of the car squished to the back seat as well.
the seat belts don't help hold the seat in place in that type of accident.spinning into a wall backwards is the same.
rob