Servicing a watch isn't just about taking it apart, cleaning it, and putting it back together. Parts wear out and need replacing (if you recall from earlier blog posts, burnishing a pivot and replacing the mainspring), cleaned jewels, pivots and moving surfaces need to be oiled and greased. Applying oil is a bit of an art, and a skill developed through a bit of repetition. Too much oil and in the wrong spots can cause your watch to run improperly or just straight up damage it.

Most of the pivots in a mechanical watch interact with a tiny ruby. When oiled properly the action between the pivot and ruby has very low friction and runs efficiently. Servicing your watch is partially about cleaning and oiling these pivots because over time the oil will degrade and get dirty. When this happens it becomes harder for your watch to run and the degraded oil and dirt will wear down your watch, best to keep them freshly cleaned and oiled on a regular interval-not after you've detected a problem.