Ground connection on a single pole round socket (Pollak)

[MaestroPNW]

Plowing along with my extra battery capacity project on the camper (batteries in the truck bed).

I got Pollak single pole connector and socket pair (http://www.etrailer.com/Wiring/Pollak/PK11852.htmland http://www.etrailer.com/p-PK11851.html)

The plug has two terminals - for power and ground. This tells me that socket should handle the ground through its body. The socket, however, does not have a dedicated attachment for the ground/negative.
It probably is designed to be mounted and be grounded to the metal frame.
My intent is to mount it in the wall of the camper, which is, obviously, not metal. Will attaching the negative cable lug to one (or both) of the mounting bolts on the inside be sufficient, or is pushing amperage through steel bolts (for a 1/4 to an inch distance) a foolish idea? Anything else I can do to reliably attach negative cable to the socket?

Thanks,
-MB

[MaestroPNW]

BurbMan wrote:
Maestro, the plug you posted the link to has ONE terminal, hence the name single pole. This plug is designed for high amperage applications for the (+) connector where the device powered is grounded through the vehicle frame. There is no provision to run a ground through the body of this connector. What you want is the 2-pole connector shown at the bottom of that page.

Actually, not quite - look at the picture below.
It has two connection points - one for positive (center plug) and the exterior lug that bind to the body of the connector. This is for negative/ground, which means it expects connectivity through the socket body.

Now, the socket itself, I guess, is expected to be grounder through the frame - you're correct there.
My question was whether connecting to the socket _body_ via mounting bolts is sufficient conductivity.

[BurbMan]

Maestro, the plug you posted the link to has ONE terminal, hence the name single pole. This plug is designed for high amperage applications for the (+) connector where the device powered is grounded through the vehicle frame. There is no provision to run a ground through the body of this connector. What you want is the 2-pole connector shown at the bottom of that page.

[WyoTraveler]

Since a lot of electrical problems on RVs are grounding problems I like good heavy chassis grounds. I grind off paint and use 3/8 inch bolts and star washers that really pick up a good ground on the chassis frame. If it is a main ground use the heaviest wire the connector will take.