They usually have a clip that holds the 6-32 screw in place. See picture- one for those who like ground up and the other for ground down.Bonding receptacle ground to a box (250.146). Exceptions? Devices with yokes listed as self grounding. How do you know the yokes are listed?
Automatic grounding clip?
Without it the receptacles need to be bonded to metal boxes? Same with switches?
A change in the 2008 NEC does not require a bonding jumper for a receptacle mounted using a crush cover.
What's a crush cover? Raised cover?