A pole tube of a solenoid actuator including a non-magnetic intermediate piece having a first intermediate end face and a second intermediate end face, a pole piece having a pole end face configured to join the first intermediate end face at a first joining region, and a tube piece having a tube end face configured to join the second intermediate end face at a second joining region. At least two of the intermediate piece, the pole piece and the tube piece are configured to be connectable to each other using electric fusion. At least two of the intermediate piece, the pole piece and the tube piece have a different conductivity. A respective part of the pole and tube pieces disposed in corresponding first and second joining regions are configured to each have an electrical resistance substantially equal to an electrical resistance of a part of the intermediate piece.