Just be a little bit wary of hardware nuts and bolts when dealing with critical items in the suspension, engine and drivetrain.
Learn to read the hardness of bolts from the markings on the head.
I was fitting a ball joint in the suspension of a Ford and found that the bolts supplied with no head markings were as soft as putty.
Obviously they were discarded and harder bolts substituted.

 

for critical strength bolts I have usedl Fastenall shops. There's one in most every majpr city.
You supply the specs or an actual sample and they get it.

 

Here is an assortment of nuts and bolts that I'm using on my XJ6C: https://www.limora.com/en/assortment...ashers/336814/
It's about $70 USD and has saved me from 40 trips to hardware store.

 

Always a day away for me and always a great selection of fine and course threads of any kind and length. McMaster-Carr

 

If only they assortments of commonly used fasteners for the XJ