The historic Rollomatic V-block shank guidance is a system whereby the concentricity of a shank during grinding is achieved by forcing the shank to rotate against the two angular surfaces of a 90 degree V-block.

With this system, the collet is only a driver and the run-out of a collet becomes less important. As an example, some Rollomatic machines can achieve a concentricity of 1 to 2 microns on the O.D., and the same accuracy on the ball shape of a ballnose endmill (example, tool dia. 1 mm).

This innovation became the trademark of Rollomatic machines already in the early stages. At present, other grinding machine builders which try to improve grinding accuracy on their machines are attempting to imitate this innovation of Rollomatic.