What should you look out for when buying a mechanical watch?

　　As a precision mechanical timekeeping instrument and decorative accessory, a mechanical watch must be both practical and decorative. A high-quality watch offers accurate timekeeping, ease of use, fine craftsmanship, and an appealing exterior. When fully wound, it can run continuously for over 36 hours and is durable, with some models also featuring water, shock, and magnetic resistance.

　　Points to note when choosing a mechanical watch:

　　1. Appearance. Visually inspect the case, dial and hands to ensure there are no pinholes or scratches, the plating is bright with no colour difference, and the case back is tightly screwed down.

　　2. Starting performance. Slowly wind the crown while observing the second hand; generally, the fewer turns required to get the second hand moving, the better the starting performance of the watch.

　　3. Winding. Winding should feel smooth with no strange noises. Apart from automatic watches which may slip when fully wound, the mainspring of a standard watch should wind fully without slipping.

　　4. Hand-setting. Setting the hands should feel comfortable, neither too tight nor too loose. The hour and minute hands should coordinate properly (when the hour hand is aligned with 3, 6, 9, and 12 respectively, the minute hand must not deviate from the 12 mark by more than ±4 minute divisions), and the hour, minute and second hands must not touch one another.

　　5. Watch ticking sound. Once the mainspring is fully wound, listen to the ticking sound of the watch; it should be clear and even with no strange noises, and should not change as the orientation changes.

　　6. Timekeeping accuracy. This needs to be measured using specialised equipment. Some large state-owned shops offer customer testing services, so you can ask the sales assistant to check the timekeeping accuracy and positional error when making your purchase.

　　Tips for selecting a watch

　　1. Check the clearance and position of the watch hands

　　There should be a certain clearance between the hands and the crystal, the dial, and between the three hands themselves; otherwise, they may rub against each other and affect the normal operation of the movement. This can be checked by adjusting the time. The method to check if the hour and minute hands are correctly aligned is: set the minute and hour hands to 3 o'clock and 9 o'clock to see if they form a right angle; set them to 6 o'clock to see if they form a straight line; set them to 12 o'clock to see if they overlap.

　　2. Inspect the exterior components of the watch

　　The exterior of the watch should be inspected for the case, crystal, dial, and hands. The case should be free of sand holes and obvious scratches, with symmetrical edges; the connection between the case back and the main case should be tight; the distance between the two lugs and the case should be equal, and the holes for the spring bars should be centred at the end of the lugs with appropriate depth to prevent the strap from falling off; the crystal should be free of defects and scratches, clear and bright; the three hands should be installed correctly, with proper safety clearance between the hands, and between the crystal and the dial; the dial and hands should have a smooth finish without blemishes, and the dial markers or luminescence should be intact; there should be a gap of approximately 0.1-0.3mm between the crown and the case. When purchasing, customers must inspect the exterior components in person (including the case, glass, hands, dial, stem, crown, lugs, strap, and bracelet). If there are any quality issues, they should be exchanged immediately to avoid future problems.

　　3. Check the sensitivity of the watch

　　1. Gently shake an unwound watch that has stopped to observe the movement of the second hand using the momentum: if the second hand stops moving within a very short time, it indicates that the watch can run down completely once fully wound (meaning the mainspring has no residual torque), indicating high sensitivity; if the second hand continues to move for a long time, it indicates that the watch cannot run down completely once fully wound (meaning the mainspring still stores torque), indicating low sensitivity or a fault in the movement.

　　2. Slowly turn the crown of an unwound watch that has stopped and observe the starting of the second hand: the fewer turns of the winding crown required for the second hand to start, the higher the sensitivity of the watch; conversely, lower sensitivity indicates lower sensitivity or other movement faults. However, note that high-frequency watches, due to the greater stiffness of the balance spring, require slightly more winding than traditional frequency (18000 vibrations/hour) movements to start. A watch with high sensitivity will run for a longer period after being fully wound once.