I haven't run across this style of connecting (?) to a screw terminal before, so I wonder if it was an approved method (ever, anywhere, but I found this in British Columbia Canada, installed ca. 1997).
This is an "Eagle" receptacle, made in Canada, and has CSA (but not UL) markings. It has rear push-in terminals.
This technique seems to provide a fair bite on the wire, but the contact area looks to be pretty small.
There doesn't seem to be any other obvious reason for the hole, but perhaps it was intended to assist in wrapping the wire around the screw? (it works quite well for that)
Place end of Conductor in hole, then wrap bare Conductor Counter Clock-Wise around Screw. Tighten Screw to 20 in.lbs, using a Calibrated Torque Wrist... Repeat technique for remaining Conductor Terminations... Mount Device to Outlet Box... Proceed to next Outlet.
Having Carpal Tunnel Syndrome / Cubital Tunnel Syndrome feels like a semi-calibrated Torque Wrist! i.e.: Wrist "Pops" at >20 in/lbs!
Scott " 35 " Thompson Just Say NO To Green Eggs And Ham!
I agree with you guys. Still not a bad idea but I bet #12 solid is not that easy to just "bend around". Maybe this is aimed at stranded? Looking at how tight the Bakelite is to the screw, I bet this is great with stranded wire.
I agree with the consensus about poking the wire in the hole and wrapping it clockwise around the screw terminal. I found a couple of Cooper/Eagle 15A resi grade receptacles on the shelf that are probably like 7-years old and they only have that hole on the grounding terminal. Same thing with the Cooper 20A single receptacles I have here. I also noticed that the 15A P&S toggle switches seem to have it on the grounding terminal as well, but I really canít say that I recall ever using it on any of them before though.
The "poke and wrap" method is exactly how they were designed; I did them that way for many years. Eagle's (Cooper's) new design has hooks embedded in the blue plastic rear housing beside each screw that now serve this purpose.
The way the one in the picture was done was entirely wrong.