I'm running some 6 ga armored bare copper wire through the attic spaces as a "grounding bus" for retrofitting grounds to various 1960s-era 2-prong receptacles. This will involve wire connections made with the 6 ga in a number of 4x4 steel junction boxes along the way in the attic, but I also want to properly bond the 6 ga to each metal junction box.
To do that, I plan to secure the 6 ga incoming wire end to a tinned lug as seen in the photo, and secure the lug to the junction box with a standard green 10-32 grounding screw and the box's pre-threaded hole for the same. The mounting hole in the lug is however 1/4 inch, so bonding connection will rely on the contact of the lug surfaces with box underneath and screw clamping from above. Is this sufficient? Kopr-shield will be used on the lug set screw and wire, and on the underneath of the lug where it contacts the box.
EDIT: @HABO The plan is to connect the end of the incoming ground wire to a lug attached to the box. Slightly upstream of that connection in the box, a split bolt would be used to connect the outgoing ground wire to the incoming wire. Any 10/12 ga EGC wire coming into the box would also be connected to the incoming ground wire via split bolt. I expect that a number of the boxes will have no EGC coming in at this point, being present for possible future use with other 2-prong outlet upgrades.
@blarg I did not find manufacturer (Southwire) provided instructions for lug mounting, but I have not made an exhaustive search. I have #6 bare armored ground wire and clamps/fittings on hand (100') and may need to add stove and/or dryer EGCs in the future, so this seemed straightforward to use.