STS-Spiral Coils, unassembled, fill outwards

The STS-spiral coil is the only brush type that can be produced with very small diameters starting at an overall diameter of 17 mm. Offering an enormous choice of dimensions and fill material qualities this brush has almost unlimited applications in light or medium work. The long period of development of this brush type has left its mark and appears in every detail of the brush. The diagram below shows how the STS coil is constructed: the fill material is fixed with a locking wire inside the backing tape.