By the way, the lubrication properties of graphite is due to the presence of fluids between the layers, such as air and water, which are adsorbed naturally, from the environment, and not solely do to the weak inter-layer bounds. In vacuum, graphite becomes a poor lubricant. In theory, if you pulled a pure graphite crystal along the direction of its planes, it would be very strong. But you would have to have a very pure crystal stack, all lined up, and be pulling at just the right direction, and pulling all layers equally. Typical graphite, like in a pencil, or more like a spaghetti-ball of layers/fragments.
