On Sun, 13 Nov 2016 15:24:36 -0800 (PST), "Gramps' shop"
wrote:

I want to tie into existing circuit for some additional grounded outlets in my basement. The existing circuit serves a half dozen or so single-bulb light fixtures. I've switched out one of those from light to three-prong receptical and have tested and determined that the box is grounded.

Question: If I run 14-2 wire from that box through metal conduit to a new metal outlet box will the new recepticals also be grounded or do I need to run a ground wire from the existing box to the new receptical?

Thanks!

Larry
If the conduit is properly installed (all the joints are tight) it is
certainly a legal grounding conductor.
A wire in the pipe is usually considered better but not required.