OK. Call Ga. Valve and fitting, ask for Linda. 1/4" brass ferrule sets are B-400-SET. They come 10 to a stick, and in 100 packs. Price is $.56 per set if you order 100, maybe a tad more if you get 10. They are in Ga., (67
-624-0949. These are sized in 1/16" increments, 300 is 3/16, 400 is 4/16 (1/4) 600 is 6/16 (3/
etc. They also carry tees, pipe thread adapters (male or female) caps, plugs, etc. Linda has been forwarned that MV collectors may be calling, she will be able to help out. Go to
www.swagelok.com and search the fitting line, you can find most everything.
My thermocouple is installed in my manifold with a 3/16 tube x 1/8 npt SS Swagelok fitting. I drilled it out to full bore size to accomodate the thermocouple, although you can buy them already drilled out (thermocouple adapters). These are serious fittings, they work just fine on high pressure hydraulic fittings.