Brake discs for commercial and passenger vehicles, supplied as spare parts for disc brake systems. The disc turns with the wheel hub and gives the brake pads a flat surface to grip, slowing the vehicle. The discs are vented, with cooling channels running between two friction faces, and have a tall machined hat section at the centre. One style carries a round flange drilled with a ring of bolt holes; another has a lobed flange, with each bolt hole set in its own raised lug. All have a bare machined metal finish.