I agree with Jerry.
Grade eight studs lubed when installed and torqued to specs.
A lot of people don't realize that the bolt or stud has to be stretched to hold it from working out.
Not friction.
If you do not lube when installing and torquing, you do not get the proper stretch.
Do a search for a torque chart for the grade bolt/studs you get.
You will be surprise at the different torque values for the same size fastener but different grade.
Don