GROUND SCREWS IN METAL JUNCTION BOXES

[infinity]

"Infinity" has a great picture for the situation! Imagine the Romex cable being Conduit in a solid run thru metal boxes Etc., The DEVICE still has to be BONDED to the box in any case, even if the code says that EMT is a suitable grounding means. Where else would you get your bonding if the device were pulled away from the box (Metal). Residential is differant from Commercial.

You're correct, but a self grounding device won't need a bonding jumper. The intimate contact between the 6-32 screw and the spring device will effectively bond the device to the box.