i built a set of bars based on this idea (thanks!) using different materials. I used 20mm black delrin bars that i bought on ebay. Was super easy.
Step 1) cut the delrin bars to the appropriate lengths (for 40cm omni spread, custom PAS @ 30mm, DINA/ORTF), of course figuring for the length of the SGC clips/capsules...
Step 2) drill holes in the ends of the delrin bars using a drill press to accomodate 1.5" 3/16 18 threaded ends... "tap handle" ends i bought from ebay.
Step 3) simply screw the threaded ends into the delrin, didn't even need glue for this
Step 4) add a pair or two of rubber washers, found some at HD that were exactly 20mm, this allows you to get the SGC clips screwed in just right so they can be lined up properly in terms of twisting them consistently
Step 5) add the SGC clips to the threaded ends and you're done.
They came out looking really great, they are continuous from the delrin to the SGC clips, can't see the screw. Super durable and fit into any 20mm shockmount. The only potential negative is that they aren't feather-light.
Will post pics of the finished product at some point, but here are the parts:
3/8-16 threaded ends:
http://pages.ebay.com/link/?nav=item.view&alt=web&id=261755397268Delrin bars (looks like the seller only currently has shorter lengths, but i would contact him, he has tons of this stuff)
http://www.ebay.com/itm/Black-Acetal-Delrin-rod-0-79-20mm-dia-4-25-/281563822176?pt=LH_DefaultDomain_0&hash=item418e82f860