Electrical wiring question

[CadiBrewer]

I'm wiring up a simple ceramic light socket to use as a heater in my fermentation chamber. I bought a metal junction box, a three prong replacement power cord, and a ceramic light socket. The ceramic socket does not have a grounding wire. Do I ground the wire from the cord to the metal box with a screw, or do I abandon the ground wire with a wire nut?

 

[RDbrew]

You need to ground the J-box with the ground provided.

 

[CadiBrewer]

Thanks for the quick response.