The present invention relates to carbon materials comprising carbon nanotubes, powders comprising carbon nanotubes and methods of making carbon nanotubes. In the methods of the present invention, the size and/or formation of floating catalyst particles is closely controlled. The resulting carbon nanotubes typically exhibit armchair chirality and typically have metallic properties. The carbon nanotubes produced by this method readily form bulk materials, which typically have a conductivity of at least 0.7×106 Sm″1 in at least one direction. The invention has particular application to the manufacture of components such as electrical conductors. Suitable electrical conductors include wires (e.g. for electrical motors) and cables (e.g. for transmitting electrical power).