>>6123311There's a bit more than that. You remember what you learn in chemistry class about metallic bonding? How there is "sea of electrons" bla bla? This bonding can occur(weakly) across two metallic surfaces and when they are shifted, relatively more material is lost. This causes metal-to-metal interfaces to have low wear-resistance.
In industrial use, there is always some plastic bushing, bearing assembly, lubrication etc. between such connections.
