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The lost wax casting method (or micro-fusion) is another technique of disposable shaping whereby a wax model is prepared, usually by means of pressure casting, and is volatilized in an oven thus generating a cavity which is then filled with cast metal. The first step therefore involves producing the wax models with each mould making one piece. After having placed the models in a cluster, complete with an alimentation channel which is also made of wax, it is covered with a ceramic paste followed by a watery refractory mixture which is then solidified (investment casting). The thickness of the covering material must be sufficient to resist the heat and pressure when the cast metal is put in. If necessary, the covering of the cluster of models can be repeated until the density of the covering has the characteristics necessary to resist the heat. At this point the structure is placed in the oven where the wax melts and it becomes, volatilised, leaving the shape ready to be filled with metal. The objects created by this method are very similar to the original and are accurate in detail. Benefits: · high quality surface; · production flexibility; · reduction of dimensional tolerance; · possibility of using different alloys (ferrous and non – ferrous).