Deposition techniques for DLC coatings are well known. Current problems relates primarily on the application of these coatings to machine elements and components. For application of these coatings it is therefore necessary to perform research studies to confirm their actual performance in real systems. Mechanisms for lubrication of steel/steel are known, but much less is clear or even un-known for steel/DLC and DLC/DLC contacts. Contributions that relates to these studies represent both basic studies and understanding, but also the practical use of DLC coatings under real operating conditions. Results of our group that were obtained so far, consists of knowledge of practical use and basic understanding, as can be seen from our patents, SCI journal papers and conference presentations.