What is the Normal Daily Rate Deviation for a Mechanical Watch?

　　Mechanical watches rely on internal mechanical components to regulate consistent and accurate timekeeping. These mechanisms are susceptible to factors such as gravity and ambient temperature, which can cause deviations. Generally, the accuracy of a mechanical watch is measured on a daily basis. So, what is the daily tolerance range for a mechanical watch?

　　Mechanical watch tolerance range

　　(1) The precision of a watch varies depending on the type of movement. Quartz watches replace the balance wheel found in mechanical watches with a quartz oscillator, using its precise high-speed oscillations for timekeeping. Generally speaking, quartz watches offer higher precision; the Swiss standard is a monthly deviation within 15 seconds, with some high-precision movements achieving a deviation of only a few seconds per year.

　　(2) Mechanical watches rely on internal mechanical components to regulate consistent and accurate timekeeping. These mechanisms are susceptible to factors such as gravity and ambient temperature, which can cause deviations. Generally, the accuracy of a mechanical watch is measured on a daily basis and varies according to the calibre model and manufacturing quality. A daily deviation within 30 seconds is typically considered normal. Some high-precision movements, such as those in chronometer series, can achieve a deviation of around 10 seconds.

　　Causes of mechanical watch timekeeping errors

　　Insufficient power: If you notice a quartz watch suddenly running slow, it is likely due to low battery power. You may take the watch to an authorised service centre to have the battery level checked.

　　Insufficient power reserve: You should first check if the power reserve is adequate. For automatic watches, low activity levels may lead to insufficient power. You can manually wind the watch to replenish the power and then observe whether the timing issue persists.

　　Magnetisation: If the hairspring of a mechanical watch becomes magnetised, the watch will no longer keep accurate time.

　　Maintenance required: Lack of lubrication in the movement or worn and aged internal components can cause timekeeping issues, requiring service at a designated repair centre.

　　Impact or shock: Watches are highly precise instruments; if subjected to impact or drops, it may cause internal components to loosen or become damaged, leading to timekeeping issues.

　　Tips for adjusting time and maintenance

　　1. Please use and adjust the watch correctly. Before using an automatic mechanical watch for the first time, it must be wound manually, but remember not to overwind it so as to avoid damaging the movement and jamming the mechanism. Take care to gently pull and push the crown when adjusting, without using excessive force. Once adjusted, ensure the crown is pushed fully back in to prevent water resistance failure caused by an unsealed crown!

　　2. All mechanical watches have a bedding-in period. During this period, a daily rate variation of plus or minus one minute within 24 hours is considered normal. Once the bedding-in period has passed and the watch enters a stable phase, a secondary adjustment can be made! The bedding-in period is generally set at three months!

　　3. For multi-functional models, take care not to press the chronograph pushers arbitrarily, and remember not to press them in rapid succession! The chronograph function should not be used when the mainspring is fully wound. The sapphire crystal must not rub against diamonds or other glass surfaces!

　　4. Time-setting method for calendar watches:

　　A. First, pull the crown out to the time-setting position and rotate it clockwise until the date changes; this indicates it is 24 AM. If adjusting before 12 PM, rotate the hour and minute hands clockwise to the desired time; if adjusting after 12 PM, rotate the hour and minute hands anti-clockwise to the desired time.

　　B. Use the quick-set corrector button to adjust the date and day display to the required date and day of the week.

　　C. The day wheel changeover is permitted to complete within 4 hours after the date changes.

　　D. For single-calendar watches, do not use the quick-set corrector button between 11 pm and 1 am every night. For day-date watches, do not use the quick-set corrector button between 11 pm and 5 am every night.