A fuel pump for a direct injection system and comprising: a main body ; a pumping chamber defined in the main body ; a piston , which is mounted in a sliding manner on the inside of the pumping chamber so as to cyclically vary the volume of the pumping chamber ; an intake duct , which ends in the pumping chamber ; an intake valve , which is arranged along the intake duct ; and a flow rate adjustment device provided with a control rod , which is coupled to the intake valve , and with an electromagnetic actuator , which is configured to axially move the control rod ; wherein the flow rate adjustment device comprises a containing element , which houses the electromagnetic actuator , has an open end facing the intake valve , and is connected to the main body by means of an annular weld ; and wherein the containing element comprises a first cylindrical wall inside which the electromagnetic actuator is arranged, which is in direct contact with the first cylindrical wall ; the fuel pump is characterized in that: the containing element comprises a second cylindrical wall , which is coaxial to the first cylindrical wall , has a diameter greater than a diameter of the first cylindrical wall , is arranged around the first cylindrical wall at a non-null distance from the first cylindrical wall , and is connected to the first cylindrical wall by means of a discoidal wall having an outer circular rim integral with the second cylindrical wall and an inner circular rim integral with the first cylindrical wall ; and the annular weld is obtained between the main body and the second cylindrical wall of the containing element . a main body ; a pumping chamber defined in the main body ; a piston , which is mounted in a sliding manner on the inside of the pumping chamber so as to cyclically vary the volume of the pumping chamber ; an intake duct , which ends in the pumping chamber ; an intake valve , which is arranged along the intake duct ; and a flow rate adjustment device provided with a control rod , which is coupled to the intake valve , and with an electromagnetic actuator , which is configured to axially move the control rod ; wherein the flow rate adjustment device comprises a containing element , which houses the electromagnetic actuator , has an open end facing the intake valve , and is connected to the main body by means of an annular weld ; and wherein the containing element comprises a first cylindrical wall inside which the electromagnetic actuator is arranged, which is in direct contact with the first cylindrical wall ; the fuel pump is characterized in that: the containing element comprises a second cylindrical wall , which is coaxial to the first cylindrical wall , has a diameter greater than a diameter of the first cylindrical wall , is arranged around the first cylindrical wall at a non-null distance from the first cylindrical wall , and is connected to the first cylindrical wall by means of a discoidal wall having an outer circular rim integral with the second cylindrical wall and an inner circular rim integral with the first cylindrical wall ; and the annular weld is obtained between the main body and the second cylindrical wall of the containing element . the containing element comprises a second cylindrical wall , which is coaxial to the first cylindrical wall , has a diameter greater than a diameter of the first cylindrical wall , is arranged around the first cylindrical wall at a non-null distance from the first cylindrical wall , and is connected to the first cylindrical wall by means of a discoidal wall having an outer circular rim integral with the second cylindrical wall and an inner circular rim integral with the first cylindrical wall ; and the annular weld is obtained between the main body and the second cylindrical wall of the containing element . <EOS>