Usually, the correct solenoid for a given application is the smallest one that has adequate magnetic force.

5.1. Magnetic force
The magnetic force in Newtons is the usable portion (i.e. that portion which is reduced by friction) of the mechanical force that is produced by the solenoid. It is measured at 90% of the rated voltage at normal operating temperature.

5.2. Holding force
The holding force of a solenoid is the force that is effective at the end of the stroke.

5.3. Residual force
The residual force, generated by any remaining (residual) magnetism, is the holding force that still applies after the electrical power is stopped. This force can be influenced by design features.

5.4. Return force
The return force is the force required to return the plunger from the end of stroke to the start of stroke.

5.5. Magnetic force / stroke characteristic
Traditional curves indicate the plunger movement toward the final (energised) position.