........ NEVER rely on a nut to stay tight on its own. Forget lock washers. Ever nut on a car that you care about should it fall off (think about how many you don't!) should be a self locking nut (there are half height MAS nuts for the issue with the number of threads left), safety wired and/or locktighted. FFR (and they are not the only ones, in fact I see more critical nuts with nothing more than a lockwasher than those that are properly installed) should get a good wrist slapping for selling pieces with out the proper hardware.
Personally, anything that hold the wheels on the car I don't think should have anything less than NS/MAS fasteners. With that being said, the upper A arm does not have any where near the stress as some of the other fasteners in a car. But then again, the bolts are mounted in double shear, bolt are tension fasteners. At least the are not in shear being used as a bearing surface
It is hard to tell from the picture but are those grade 5 bolts mounted in single shear holding the coil over and the inner lower A arm in place!!!! Those area DO take a lot of force.
On a roll now. Look at the tabs where the upper arms mounts. WRONG. Seems to me that those tabs should be at least half as thick as the bolt diameter. That looks like a lug used on an adjustable sway bar not an suspension A arm.
Now don't tell me that those are fully threaded bolts or that the threads go into the mounting area! I will have to really loose it then! If a bolt of the proper grip length is not available, get the next longest and use washers to properly place the nut.
Is that a cadium plated grade five holding the tie rod to the steering arm! Is that a sperical bearing in the steering arm!
The guy who talked about the grade 5 vs 8 is correct. 8 is so brittle it will usually just fail with no visable signs before hand. Where a grade 5 will often bend first. Depending on the application, that can be a plus!
I am NOT an engineer but it does seem to be some problems here. Or maybe I am just anal!
Maybe I just found a niche for myself here. Bring me a car and I will come up with a proper fastener kits. Available soon!
Rick aka 'never met a fastener I trusted Rick'