Final answer:
To polish an axle, rubbing with a cloth is commonly used after cleaning. Heating and hammering may be involved but should be approached with care to not damage the axle's properties.
Step-by-step explanation:
After cleaning the spindle with a wire brush and brake-parts cleaner, to polish the axle, you should opt for a method that is effective and safe for the material of the axle. The three given options are:
- Heating, hammering, and spinning in an external magnetic field
- Hammering, heating, and rubbing with cloth
- Cooling, submerging in water, or rubbing with cloth
Among these, the most common and suitable method for polishing an axle after it has been cleaned would be rubbing it with a cloth. The use of heat or an external magnetic field should be conducted with caution, as it may alter the properties of the metal the axle is composed of. Option c, which suggests hammering, heating, and rubbing with cloth, seems to be the most feasible, but hammering should only be done if necessary to reshape the axle, and heating should be controlled to ensure that it does not weaken the axle.