METAL TREATMENT; GRINDING; SURFACE GRINDING; ELECTROPLATING; SOLDERING; WELDING; PLATING BY ELECTROLYSIS; REMOVAL OF PROTECTIVE COATINGS; APPLICATION OF PROTECTIVE COATINGS; [ CASTING OF METAL; HARDENING OF METAL; ] ASSEMBLY AND DISMANTLING OF AERO ENGINES FOR OTHERS, IN PARTICULAR JET ENGINES, PROPELLER TURBO JET ENGINES, GAS TURBINES AND PARTS THEREOF, IN PARTICULAR ROTOR BLADES, VANES, HOUSINGS AND ROTOR PARTS AS WELL AS INTEGRALLY BLADED ROTORS; TECHNICAL CONSULTATION IN THE FIELD OF GAS ...