Up to now it has not been possible to apply soldering to graphitic materials and ceramics, as they are not wetted by the commercially available alloys. C-SOLDER® is a new tin-based lead-free low-temperature soldering alloy which enables the joining of carbon fibres or carbon nanotube fibres, ceramics and metals including aluminium. The use of C-Solder allows fast formation of mechanically strong bonds, which are electrically and/or thermally conductive simultaneously. It offers excellent wetting of carbon materials such as graphite, carbon fibres, carbon nanotube fibres, and graphene as well as excellent wetting of ceramics and of metals including aluminium without use of flux. C-Solder is not affected by cleaning solvents and does not leave residues and works with soldering temperatures below 450°C. C-Solder is lead free and flux free.