Solenoid actuator and method for making the same

A method for making a solenoid actuator comprising:

• A) assembling together two solenoid actuator tubes, a non-magnetic ring and two brazing rings all of which are aligned along an axis, the non-magnetic ring having two opposite end sections and being located between the two solenoid actuator tubes, each of the two brazing rings being disposed between one of the two opposite end sections of the non-magnetic ring and an adjacent one of the two solenoid actuator tubes, each of the two solenoid actuator tubes partially extending into a respective one of the two opposite end sections of the non-magnetic ring, a melting point of the two brazing rings being lower than melting points of each of the solenoid actuator tubes and the non-magnetic rings;
• B) heating the two brazing rings, the two solenoid actuator tubes, and the non-magnetic ring until the two brazing rings melt and until the two solenoid actuator tubes and the non-magnetic ring soften;
• C) applying pressure to the two solenoid actuator tubes, the non-magnetic ring and the two brazing rings from two opposite ends of the solenoid actuator tubes along the axis;
• and
• D) after the solenoid actuator tubes, the non-magnetic ring, and the brazing rings have cooled, conducting a machining step to form a plunger bore inside the two solenoid actuator tubes and the non-magnetic ring along the axis.