The University of Wolverhampton's Innovative Product Development Centre (IPDC), which is located on its Telford campus, has begun making metal tooling and components on short lead times using a direct metal laser sintering (DMLS) machine from EOS. The EOSINT M250 Xtended facility is just one of three currently installed in the UK. It builds functional metal parts from successive 20micron layers of metal powder fused by a laser, which is guided according to data generated from slices taken through a CAD model of the part.DMLS is particularly useful for producing complex dies with conformal cooling/heating channels. The tool is built layer by layer, leaving spaces for the channels and allowing a much more complex labyrinth of straight, curved and variable diameter cooling ducts to be created than is possible by deep-hole drilling, which in any case is only capable of producing straight holes.The channels thus conform to, or follow, the shape of the tool surface and the temperature profile across it to provide more efficient and accurate heat transfer, reducing injection moulding and die-casting cycle times and improving the quality of the parts. It is also possible to produce a tool with porous faces by adding, for example, designated areas on the tool built with lower densities. This avoids the need for a vent plug and the witness mark that is inevitably left on the plastic part.The IPDC team used to make a few conformal moulds in a plastic laser sintering machine using 100micron diameter, polymer-coated stainless steel powder, but the process was crude compared with DMLS, which builds layers of 20micron, high strength tool steel powder. The previous sintering method involved subsequent burning away of the plastic at high temperatures and then infiltrating the gaps with bronze. The former led to contraction and stability problems, while the latter was constrained by the shape of the tool. With DMLS, both problems are avoided and there is the additional benefit that the detail resolution is much higher, resulting in a better quality tool.