The rack is mainly anodized aluminum with stainless steel fasteners (screws, bolts and nuts) some brass bushings, and a few Delrin parts.
The fasteners are torqued at the factory and because of the chemical properties of steel mated to aluminum, need no thread-lock solution.
It is a good idea to occasionally check the fasteners and other parts to make sure they are secure and tight. Any mechanical connection can vibrate and loosen, so make sure this doesn’t happen to you. This is normal wear and tear.