The highly anisotropic lattice structure, with a strong atomic binding in the planar layers and a weak one in the perpendicular direction, gives pyrolytic graphite extraordinary properties. The mechanical strength, electrical conductivity, magnetic properties, and thermal expansion reflect this anisotropy. The degree of anisotropy depends on how parallel the planar layers are. This is characterized by a term called mosaic spread angle, and as the number becomes smaller, it gives a higher parallelism and thus a more perfect lattice.

