In the box-shaped OKTA mould, all the outer surfaces of the areas to be cast are at an equal distance of 10 mm to the casting object. This enables the melted mass to cool and solidify consistently which in turn allows the adjustable contraction of the casting object. Precision fit is the result. There are no heat pockets as found in the round cylindrical mould used with the conventional model casting technique. Once the material has hardened, the plastic elements are removed and the octagon mould is preheated in stages according to the instructions. The cast made of the CoCrMo alloy SAE OKTA-M VS is produced in the HF vacuum casting machine.