I've never seen a stud break in my life. With cars new up to 15 years old, the tires have been taken off hundreds or even a thousand times.
I went to a car shop in Mexico that said my brake pads need changing, and after changing them I measure the thickness at about 8mm, or way before (5mm of 12mm new left) needing changing.
Then I discovered that 3 studs were broken by them. They replaced them free but while replacing them, the studs keep breaking every time they take off the wheels to put the new ones on.
This has happened about 8 or 9 times. He is tightening the lug nuts by hand, but the first three that broke, must have been tightened by someone else. What is causing this? Should I just pay another mechanic or risk having it done free and keep breaking?
More details, I watched him un-screw it and what happens is while unscrewing the lug nut becomes jammed between two degrees say between 9 and 3 o'clock. He then has to use more force and the stud then breaks.