What is the smoothness of the contact area of Aavid extrusions?
The contact area between object and heatsink is important and should be as smooth as possible.
To guaranty a good thermal conduction TIM could be used. Or greases and pastes.
https://www.digikey.com/short/z7ttbf
Aavid has some info available about the smoothness of their extrusions. See below.
