Whereas spark erosion and lasermachining are suitable for any metal, the use of mechanical precision machining and the tools suitable for this type depend on the stability of the alloy. For brass and copper, natural diamondmicrotools are suitable and widely used, while for stainless steel and nickel- based alloys, hardmetal tools are needed. Figure shows a natural diamond cutter, whereas Figure shows a hard metal drill. Figure shows photos of a rhodium honeycombmicrochannel catalyst system. The channels have beenmachined bywire spark erosion and therefore show a semicircular face area that is shown in detail
