Method of manufacturing an object comprising the following successive steps: a) casting liquid iron into a mold having a shaped surface, b) the liquid iron is allowed to solidify to obtain a blank of the object, c) the object blank is subjected to a heat treatment, in particular a stress relief treatment, to obtain the cast iron object, wherein the object is made of spheroidal graphite cast iron, wherein the spheroidal graphite cast iron comprises, in % by weight, the following elements: - Carbon less than or equal to 3.65%, - Silicon (Si) between 3.3% and 3.7%, Optionally: - Phosphorus ≤ 0.1%, and/or - Manganese (Mn) ≤ 0.6%, and/or - Chromium (Cr) ≤ 0.2%, and/or - Titanium (Ti) ≤ 0.15%, and/or - Sulfur ≤ 0.05%, and/or - Magnesium (Mg) between 0.005% inclusive and 0.07% inclusive, and/or - Copper (Cu) ≤ 0.3%, and/or - Nickel (Ni) ≤ 0.4%, and/or - Molybdenum (Mo) ≤ 0.02%, and/or - Aluminum (Al) ≤ 0.02%, and/or - Vanadium ≤ 0.04%, the remainder being iron (Fe), and residual elements that are unavoidable at contents less than 0.01%, in which the spheroidal graphite cast iron has a carbon equivalent C EQ = C (%) + 1/3 Si (%) + 1/3 P (%) less than or equal to 4.75%, and in which the spheroidal graphite cast iron has a resilience greater than or equal to 9.49 J at 20°C, measured according to AWWA C151, method in which the shaped surface is free from a temporary thermal insulator or a temporary refractory material when casting the molten iron into the mold, and wherein the heat treatment comprises: - a first step of heating the blank of the object for a time of between 2 and 10 minutes until a graphitization temperature of greater than 800°C is reached, but lower than 1000°C, this first step relaxing the internal stresses initially present in the casting, - a second graphitization step during which the blank of the cast iron object is maintained at the graphitization temperature for a period of between 5 and 30 minutes, - a third cooling step to a temperature of between 880°C and 750°C of a duration of less than 7 minutes, and - a fourth ferritization step during which the blank of the cast iron object is cooled slowly, at a rate of less than 40°C/minute, within a temperature range of between 700°C and 780°C. a) casting liquid iron into a mold having a shaped surface, b) the liquid iron is allowed to solidify to obtain a blank of the object, c) the object blank is subjected to a heat treatment, in particular a stress relief treatment, to obtain the cast iron object, wherein - Carbon less than or equal to 3.65%, - Silicon (Si) between 3.3% and 3.7%, - Phosphorus ≤ 0.1%, and/or - Manganese (Mn) ≤ 0.6%, and/or - Chromium (Cr) ≤ 0.2%, and/or - Titanium (Ti) ≤ 0.15%, and/or - Sulfur ≤ 0.05%, and/or - Magnesium (Mg) between 0.005% inclusive and 0.07% inclusive, and/or - Copper (Cu) ≤ 0.3%, and/or - Nickel (Ni) ≤ 0.4%, and/or - Molybdenum (Mo) ≤ 0.02%, and/or - Aluminum (Al) ≤ 0.02%, and/or - Vanadium ≤ 0.04%, the spheroidal graphite cast iron has a carbon equivalent C EQ = C (%) + 1/3 Si (%) + 1/3 P (%) less than or equal to 4.75%, and in which the spheroidal graphite cast iron has a resilience greater than or equal to 9.49 J at 20°C, measured according to AWWA C151, method in which the shaped surface is free from a temporary thermal insulator or a temporary refractory material when casting the molten iron into the mold, and wherein the heat treatment comprises: - a first step of heating the blank of the object for a time of between 2 and 10 minutes until a graphitization temperature of greater than 800°C is reached, but lower than 1000°C, this first step relaxing the internal stresses initially present in the casting, - a second graphitization step during which the blank of the cast iron object is maintained at the graphitization temperature for a period of between 5 and 30 minutes, - a third cooling step to a temperature of between 880°C and 750°C of a duration of less than 7 minutes, and - a fourth ferritization step during which the blank of the cast iron object is cooled slowly, at a rate of less than 40°C/minute, within a temperature range of between 700°C and 780°C. - a first step of heating the blank of the object for a time of between 2 and 10 minutes until a graphitization temperature of greater than 800°C is reached, but lower than 1000°C, this first step relaxing the internal stresses initially present in the casting, - a second graphitization step during which the blank of the cast iron object is maintained at the graphitization temperature for a period of between 5 and 30 minutes, - a third cooling step to a temperature of between 880°C and 750°C of a duration of less than 7 minutes, and - a fourth ferritization step during which the blank of the cast iron object is cooled slowly, at a rate of less than 40°C/minute, within a temperature range of between 700°C and 780°C.