The invention concerns a casing aggregate for the turbine of an exhaust turbocharger. The invention is identified by the following characteristics:

• a spiral casing adapted for surround the running wheel of the turbine;
• a tongue-like wall part (tongue) in the inside of the spiral casing;
• an inlet connection;
• an outlet connection;
• a flange to connect to a bearing casing;
• wherein the casing aggregate is manufactured of thin-walled precision casting;
• wherein the casing aggregate is made of at least two parts, so that at least one separation joint is present; and
• the separation joint is arranged as follows:
  • it runs in an axially perpendicular level;
  • it runs along the apex line of the spiral casing;
  • it extends over an arc of a circle of approximately 270 degrees;
  • it lies outside of the area of the tongue.