A coated steel stamped product, which comprises: (a) a strip of base steel having a first side and a second side, the steel in the strip having a composition comprising, by weight: 0.15 ⁢ % < carbon < 0.5 ⁢ % 0.5 ⁢ % < manganese < 3 ⁢ % 0.1 ⁢ % < silicon < 0.5 ⁢ % 0.01 ⁢ % < chromium < 1 ⁢ % titanium < 0.2 ⁢ % aluminum < 0.1 ⁢ % phosphorus < 0.1 ⁢ % sulfur < 0.05 ⁢ % 0.0005 ⁢ % < boron < 0.08 ⁢ %, and further comprises iron and impurities inherent in processing; and (b) a coating on at least one of said first side of said strip of base steel and said second side of said strip of base steel, wherein: (i) said coating results from the interdiffusion between said base steel, and aluminium or aluminium alloy pre-coating, (ii) said coating comprises, proceeding from base steel outwards, - (a) Interdiffusion layer, having the following composition, by weight: 86-95% Fe, 4-10% Al, 0-5% Si; - (b) Intermediate layer, having the following composition, by weight: 39-47% Fe, 53-61% Al, 0-2% Si; - (c) Intermetallic layer - (d) Superficial layer, having the following composition, by weight: 39-47% Fe, 53-61% Al, 0-2% Si; wherein said layers (c) and (d) are occupying at least 90% of the level corresponding to the considered said layers and wherein less than 10% of layer (c) is present at the extreme surface of the product. (a) a strip of base steel having a first side and a second side, the steel in the strip having a composition comprising, by weight: 0.15 ⁢ % < carbon < 0.5 ⁢ % 0.5 ⁢ % < manganese < 3 ⁢ % 0.1 ⁢ % < silicon < 0.5 ⁢ % 0.01 ⁢ % < chromium < 1 ⁢ % titanium < 0.2 ⁢ % aluminum < 0.1 ⁢ % phosphorus < 0.1 ⁢ % sulfur < 0.05 ⁢ % 0.0005 ⁢ % < boron < 0.08 ⁢ %, and further comprises iron and impurities inherent in processing; and (b) a coating on at least one of said first side of said strip of base steel and said second side of said strip of base steel, wherein: (i) said coating results from the interdiffusion between said base steel, and aluminium or aluminium alloy pre-coating, (ii) said coating comprises, proceeding from base steel outwards, - (a) Interdiffusion layer, having the following composition, by weight: 86-95% Fe, 4-10% Al, 0-5% Si; - (b) Intermediate layer, having the following composition, by weight: 39-47% Fe, 53-61% Al, 0-2% Si; - (c) Intermetallic layer - (d) Superficial layer, having the following composition, by weight: 39-47% Fe, 53-61% Al, 0-2% Si; (i) said coating results from the interdiffusion between said base steel, and aluminium or aluminium alloy pre-coating, (ii) said coating comprises, proceeding from base steel outwards, - (a) Interdiffusion layer, having the following composition, by weight: 86-95% Fe, 4-10% Al, 0-5% Si; - (b) Intermediate layer, having the following composition, by weight: 39-47% Fe, 53-61% Al, 0-2% Si; - (c) Intermetallic layer - (d) Superficial layer, having the following composition, by weight: 39-47% Fe, 53-61% Al, 0-2% Si; - (a) Interdiffusion layer, having the following composition, by weight: 86-95% Fe, 4-10% Al, 0-5% Si; - (b) Intermediate layer, having the following composition, by weight: 39-47% Fe, 53-61% Al, 0-2% Si; - (c) Intermetallic layer - (d) Superficial layer, having the following composition, by weight: 39-47% Fe, 53-61% Al, 0-2% Si;