Two families of tools are offered, the first uses PCD contour blades and is intended for pre-machining and conditioning of cylinder bore surfaces before metal spraying, while the second family comprises tools with PcBN blades for dressing the surfaces after spraying.

At present, the bores of most aluminium cylinder crankcases are lined with cast or shrink-fit grey iron bushes. Replacing the bushes with thermally sprayed ferrous metal coatings allows lighter and more compact engine blocks to be produced, but this new technology brings with it new machining challenges.

To address these, MAPAL has developed the PCD contour blade tools so that they create a defined structure on the cylinder bore to prepare it for spraying. This structure has been designed to prevent blistering and inhomogeneity in the sprayed coating, and it also features small undercuts to ensure optimum coating adhesion.

MAPAL fine machining tools with HX inserts for use after spraying prepare the bore surfaces for final precision honing. Since the hard-sprayed coatings place a very high load on the cutting edges, cutting blades with a specially selected grade of PcBN are used. The fine machining tools can also incorporate coolant-controlled actuator mechanisms and cutting compensation if required.