Within reason, a mechanical watch can always be brought back into good time keeping, and a jeweled movement can last for generations.

However, it is important to periodically service a watch to ensure that the components are well-lubricated, and that the mechanism is free from dust, dirt, and  moisture. Any water that gets inside a mechanical watch will wreak havoc with the precision mechanism inside, especially the anchor escapement and escape wheel which are typically made of steel.

The typical rule of thumb is to have the water resistance (i.e., the integrity of the seals in the crown, bezel, and caseback) of a watch checked every year or so, especially if used for sports or diving. With the development of modern synthetic lubricants, most manufacturers recommend a servicing every four or five years.

Certain Sinn watches used enhanced technologies to extend therecommended service interval.  For example, the DIAPAL series uses an oil-free escapement, and can go up to seven years before service is required.

Sinn watches containing inert gasses or copper sulphate capsules offer added protection against water and humidity.

(portions used with permission of TimeZone)