We use stainless steel element terminal bolts. Stainless steel bolts have weaker threads than plated bolts but resist corrosion much better (which is more important in high temperature environments with corrosive fumes).
On a new kiln the factory tightens the nuts on the bolts for a good connection. It is hard to cross thread on a new kiln bolt easily as a cross threaded nut will not turn on the bolt more than 1/2 a turn or so.
There is a fine line on the element connections between tight enough and over tight. It is possible to break bolts when replacing the elements even ones that are relatively new. Part of this can be attributed to the relative lack of strength in stainless steel.
Heat, vibration and element stress can wear the thread on the bolt.
Generally it is easy to replace a bolt.
We suggest changing all the stainless steel terminal hardware when changing elements.