LOS Vacuum has finished their first production run of LOS 2.75″ CF style flanges made from 304 stainless steel. These flanges feature a very high quality surface finish on all surfaces.
Special attention is given to the surfaces exposed to vacuum to reduce total surface area and outgassing. The outside diameter of our flanges is turned complete at the same time as the knife edge eliminating any run out or concentricity issues. After manufacturing, our flanges are cleaned in our Branson ultrasonic cleaning tank. LOS also manufactures all CF style flanges from Titanium as well. If the magnetic properties, or hydrogen content of stainless steel is a concern for you then Titanium could be the answer.
When trying to reach ultra and extreme high vacuum levels of 1 x 10^-10 Torr and higher one needs to pay attention to the hydrogen content of steel as it does outgass and will not allow you achieve these levels of vacuum. When operating in the high vacuum range of 1 x 10^-7 Torr down to 1 x 10^-9 Torr one can effectively use stainless steel components, however baking out a stainless steel chamber to degas a system can be time consuming. Titanium bakes-out faster and more uniformly even at lower temperatures.