Bosch aluminum dough hook has black coating (by 2 users)

the problem is where the pin on the beater shaft locks into the hook may be wearing down or the hook itself.when you put the hook on see if you get alot of play in the hook (wiggle it and if it feels really loose its worn).its still safe to use but eventually (and this may be quite sometime) the pin may break off the beater shaft.you would then have to replace the pin and hook.