Abstract: A mounting for an object processed at a predetermined temperature in an uahigh vacuum chamber having a stainless steel wall. The mounting has a stainless steel tube welded to the wall and opening through it and has an oxygen-free-high-conductivity copper finger extended from the tube to receive the object. At the junction of the tube and the finger, the tube bears an annular knife edge which engages a flat surface of the finger, and an ultrahigh vacuum seal is established by a collar and bolt coupling which draws the finger against the knife edge. The temperature of the finger and the object are then controlled and measured by cryogenic liquids, electrical heaters, and sensors inserted through the tube into contact with the finger.