[Jeff, Ian, Sander, Daniel]

We tipped over a 10" vacuum cube like we did before so that we could replace the bottom CF Flange with one that I tapped. 

We vented the vacuum oven from ~0.2 atm to 1 atm and grabbed one of the custom flanges that I tapped. We attached the CF flange to the cube with a new method courtesy of Maty Lesovsky: screw in a few screws at the bottom of the flange, tip the flange so the bottom is touching the cube and the top is exposed, then drop in the copper gasket. We took off the screws and rotated the flange to ensure the gasket was in the correct place.

We tried to use silver-plated 1.75" long 5/16-24 screws to secure the flange to the cube, but we couldn't thread them in deep enough so that the head (and washer) made contact with the flange. We therefore attached the 1.75" screws with hex heads through the custom base I had made to secure the flange and replaced the silver plated 1.75" long screws with silver plated 1.5" long screws. We could use the 1.75" screws with hex heads becuase the custom part I made puts the heads ~0.25" from the flange. I noticed that I partially stripped some of the silver plated 1.75" screws.

After screws of an appropriate length were inserted, I tightened them in a star pattern with a torque wrench, starting at 13 Nm and ending at 34 Nm, with increments of 6.8 Nm. By the time I went around the flange at 34 Nm a few times and no screw was further tightened, the flange was very close or touching the cube everywhere.

See this post for images of a similar procedure.