SEIKO Calibers 4R35/4R36/4R37/4R38/4R39 Mechanical Watch User Manual
Introduction
This manual provides detailed information for SEIKO mechanical watches utilizing calibers 4R35, 4R36, 4R37, 4R38, and 4R39. These watches feature both automatic and manual winding capabilities.
Characteristics of Mechanical Watches
The power source for these mechanical watches is the mainspring.
- If the watch has stopped, manually wind the mainspring by rotating the crown approximately 20 times.
- Unlike quartz watches, the accuracy of mechanical watches is measured by daily variation (gain or loss per day).
- Accuracy can be influenced by usage conditions such as wearing frequency, ambient temperature, hand movements, and the degree of mainspring winding.
- Exposure to strong magnetic fields can temporarily cause the watch to gain or lose time, and may magnetize internal parts. If this occurs, seek professional demagnetization at a store where the watch was purchased.
Part Names and Crown Positions
The dial and crown functions vary slightly by caliber. The crown typically has three positions:
- [Position a] (Initial): Manual winding of the mainspring.
- [Position b] (First Click): Setting the date and/or day of the week.
- [Position c] (Second Click): Setting the time.
Caliber 4R35: Features hour, minute, second hands, and a date display.
Caliber 4R36: Features hour, minute, second hands, and displays for both date and day of the week.
Caliber 4R37: Features hour, minute, second, and 24-hour hands, along with a date display.
Caliber 4R38: Features hour, minute, second hands.
Caliber 4R39: Features hour, minute, second, and 24-hour hands.
Diagram Description: Visual representations of watch dials for each caliber would show the arrangement of Roman numerals or markers, the positions of the hour, minute, and second hands, the date/day windows, and the 24-hour indicator where applicable. The crown is shown with labels indicating positions 'a', 'b', and 'c' for setting functions.
Usage
These watches are equipped with both automatic and manual winding functions.
- Automatic Winding: When worn on the wrist, the mainspring is wound automatically by the natural motion of your arm.
- Manual Winding: If the watch has stopped, it is recommended to wind it manually by rotating the crown.
How to Wind Manually:
- Slowly rotate the crown clockwise (towards the 12 o'clock position). Rotating the crown counter-clockwise (towards 6 o'clock) does not wind the spring.
- Continue rotating until the mainspring is fully wound. The second hand will begin to move.
A fully wound mainspring provides approximately 41 hours of operation.
Diagram Description: An illustration shows a watch dial with hands and an arrow indicating the direction of crown rotation for manual winding (clockwise).
Setting Time and Date
Ensure the watch is running before proceeding with time and date settings.
For Calibers 4R35 and 4R37 (Date Setting)
The date is displayed on a sub-dial and typically changes around midnight (12 AM). Incorrect AM/PM setting can cause the date to change at noon.
- Pull the crown out to the first click [Position b]. The second hand will continue to move.
- To set the date, rotate the crown counter-clockwise. Rotate until the desired date appears. For example, if today is the 5th, set the display to '4' to advance it to '5' when you set the time.
- WARNING: Do not set the date between 9:00 PM (21:00) and 1:00 AM. Doing so may cause the date to change incorrectly and lead to malfunction.
- Pull the crown out to the second click [Position c], when the second hand is at the 12 o'clock position (it will stop).
- Rotate the crown to set the hour and minute hands to the current time. It is recommended to set the minute hand slightly before the desired time and then advance it to the exact minute mark.
- Return the crown to its initial position [Position a] in sync with an accurate time signal.
For Caliber 4R37: This caliber includes a 24-hour hand that moves in sync with the hour hand. Ensure the 24-hour hand is set correctly when setting the time.
Diagram Description: Illustrations show the watch dial and crown positions for setting the date and time. For the 4R37, a separate dial showing 24-hour markings is depicted, with the 24-hour hand indicated.
For Caliber 4R36 (Day and Date Setting)
The date and day of the week are displayed on sub-dials and change every 24 hours (date around midnight, day around 4 AM). Incorrect AM/PM setting can cause the date to change at noon and the day at 4 PM.
- Pull the crown out to the first click [Position b]. The second hand will continue to move.
- To set the day, rotate the crown clockwise.
- To set the date, rotate the crown counter-clockwise. Rotate until the desired date appears. For example, if today is the 5th, set the display to '4' to advance it to '5' when you set the time.
- Pull the crown out to the second click [Position c].
- Rotate the crown to set the hour and minute hands to the current time.
- Return the crown to its initial position [Position a] in sync with an accurate time signal.
WARNING: Do not set the date between 9:00 PM (21:00) and 4:00 AM. Doing so may cause the date to change incorrectly and lead to malfunction.
Diagram Description: Illustrations show the watch dial and crown positions for setting the day, date, and time for the 4R36 caliber.
Correcting the Date at the Beginning of the Month
Manual correction is required at the end of months with fewer than 31 days (e.g., April, June, September, November).
Example: Setting the date to the 1st of a month following a 30-day month.
- If the watch shows "31" instead of "1", pull the crown out to the first click [Position b].
- Rotate the crown to set the date to "1". Return the crown to its initial position [Position a].
WARNING: Do not set the date between 9:00 PM (21:00) and 1:00 AM (or 4:00 AM for 4R36). Doing so may cause the date to change incorrectly and lead to malfunction.
Diagram Description: Shows the date display on the watch face and the crown being pulled out to the first click for adjustment.
For Calibers 4R38 and 4R39 (Time Setting)
- Pull the crown out to the second click [Position c], when the second hand is at the 12 o'clock position (it will stop).
- Rotate the crown to set the hour and minute hands to the current time.
- Return the crown to its initial position [Position a] in sync with an accurate time signal.
For Caliber 4R39: This caliber includes a 24-hour hand that moves in sync with the hour hand. Ensure the 24-hour hand is set correctly when setting the time.
Diagram Description: Illustrations show the watch dial and crown positions for setting the time for calibers 4R38 and 4R39. For the 4R39, a separate dial showing 24-hour markings is depicted, with the 24-hour hand indicated.
Preserving the Quality of Your Watch
Care for Your Watch
- Under normal circumstances, your watch requires no special care and will function for many years.
- To ensure durability and prevent skin irritation, wipe off moisture, sweat, or dirt with a soft, dry cloth immediately after removing the watch.
- Leather Strap: Gently blot moisture from the strap using a soft, dry cloth. Do not rub the leather, as this may cause damage or discoloration.
- Metal Bracelet: To clean the bracelet, use a soft toothbrush dampened with clean or soapy water. Be careful not to let water get into the watch case.
Skin Irritation and Allergic Reactions
- Adjust the strap to allow a small gap between the strap and your wrist for ventilation.
- In some individuals, prolonged contact with the watch may cause skin irritation or allergic reactions.
- Possible causes of dermatitis include:
- Allergic reactions to metals or leather.
- Rust, dirt, or sweat accumulated on the watch or strap.
- If you experience any allergic symptoms or skin irritation, stop wearing the watch immediately and consult a doctor.
Water Resistance
The water resistance rating is indicated on the case back of the watch.
- No Water Resistance: If the word "WATER RESISTANT" is not written on the case back, the watch is not water-resistant. Avoid getting it wet, as water can damage the movement. If the watch gets wet, take it to the store where it was purchased or a SEIKO SERVICE CENTER for inspection.
- Water Resistance (3 Bar): If "WATER RESISTANT" is written on the case back, the watch is designed to withstand pressure up to 3 Bar. It can resist accidental contact with splashes of water or rain but is not intended for swimming.
- Water Resistance (5 Bar): If "WATER RESISTANT 5 BAR" is written on the case back, the watch can withstand pressure up to 5 Bar and can be used while swimming, sailing, and showering.
- Water Resistance (10 Bar / 15 Bar / 20 Bar): If "WATER RESISTANT 10 BAR", "WATER RESISTANT 15 BAR", or "WATER RESISTANT 20 BAR" is written on the case back, the watch can withstand pressure up to 10 (15, 20) Bar. It can be used while bathing or for shallow-water diving, but not for scuba diving. SEIKO Diver's watches are recommended for scuba diving.
* Before using a watch with 5, 10, 15, or 20 Bar water resistance in water, ensure the crown is fully pushed in. Do not operate the crown if the watch is wet or submerged. If the watch has been used in saltwater, rinse it with fresh water and dry it completely.
When showering with a 5 Bar watch, or bathing with a 10, 15, or 20 Bar watch, please observe the following:
- Do not operate the crown when the watch is in soapy water or shampoo.
- Exposure to warm water may temporarily affect the watch's accuracy. Accuracy will be restored once the watch returns to normal temperature conditions.
MEMO: Bar pressure is a test pressure and should not be considered equivalent to actual diving depth, as swimming movements can increase pressure at a given depth. Exercise caution when diving with your watch.
Precautions When Wearing Your Watch
- Be cautious when holding infants or small children while wearing the watch on your wrist, as the child may be injured or develop an allergic reaction from direct contact with the watch.
- Avoid impacts, drops, scratches on hard surfaces, and strenuous sports activities that could cause temporary malfunctions.
- There is a risk of injury if you fall or collide with others or objects while wearing the watch on your wrist.
Where to Store Your Watch
- Do not store the watch in places exposed to strong magnetic fields (e.g., near televisions, speakers, or magnetic bracelets) or static electricity.
- Do not store the watch in places with strong vibrations.
- Do not store the watch in dusty locations.
- Do not expose the watch to chemicals or gases (e.g., organic solvents like gasoline and solvents, nail polish, cosmetic sprays, detergents, glue, mercury, and iodine-based antiseptics).
- Avoid direct contact of your watch with hot water.
Periodic Checks
These watches are precise instruments with many moving parts lubricated by special oil. They require periodic checks as insufficient lubrication or wear can lead to inaccurate timekeeping or stoppage.
Warranty and Repair Tips
- For repairs or inspections, please contact the store where you purchased the watch or a SEIKO SERVICE CENTER.
- Present your warranty certificate when seeking service within the warranty period.
- Warranty terms are detailed in the warranty certificate. Please read it carefully and keep it.
Troubleshooting
| Problem | Possible Cause | Possible Solution |
|---|---|---|
| Watch stopped | Mainspring energy depleted | Wind the watch manually or shake it like a pendulum. If it still does not run, contact the store for inspection. |
| Stops frequently despite daily wear | Worn for too short a period, or insufficient hand movement. | Wear the watch for a longer period, or wind the mainspring manually when not wearing it. |
| Gains or loses time | Exposed to extreme temperatures for a long time. | Return the watch to normal temperature; accuracy should recover. |
| Gains or loses time | Left near a strong magnetic field for a long time. | Remove the watch from the magnetic field; accuracy should recover. If this does not help, contact the store where the watch was purchased. |
| Gains or loses time | Dropped, impacted against a hard surface, or worn during strenuous sports. Subjected to strong vibrations. | Contact the store where the watch was purchased. |
| Date changes at 12 PM (AM/PM incorrect) | Incorrect AM/PM setting. | Advance the hour hand by 12 hours. |
| Condensation inside the glass remains for an extended period. | Water ingress due to gasket damage. | Contact the store where the watch was purchased. |
| Watch not checked for over 3 years. | N/A | Contact the store where the watch was purchased. |
• For any other issues, please contact the store where the watch was purchased.
Accuracy of Mechanical Watches
- The accuracy of mechanical watches is indicated by daily variation.
- The accuracy may deviate from the specified range due to factors like usage conditions, duration of wear, hand movements, and mainspring winding.
- The main components are made of metals that expand or contract with temperature, affecting accuracy. Mechanical watches may slow down in high temperatures and speed up in low temperatures.
- To maintain accuracy, it is crucial to regularly supply energy to the balance wheel, which controls the escapement. The force from the mainspring is not uniform throughout its unwinding.
- Consistent accuracy can be achieved with regular wear for automatic watches and daily full winding for manual-winding watches.
- Exposure to strong external magnetic fields can temporarily affect accuracy. Internal parts may become magnetized depending on the field strength. In such cases, consult the store where the watch was purchased, as it may require servicing, including demagnetization.
Specifications
| # | Characteristic | Details |
|---|---|---|
| 1 | Caliber | 4R35: Three hands (hour, minute, second), date display. 4R36: Three hands (hour, minute, second), date and day displays. 4R37: Four hands (hour, minute, second, 24-hour), date display. 4R38: Three hands (hour, minute, second). 4R39: Four hands (hour, minute, second, 24-hour). |
| 2 | Beats per hour | 21,600 |
| 3 | Operating temperature range | -10 °C to 60 °C (14 °F to 140 °F) |
| 4 | Power reserve (fully wound) | Slightly over 41 hours |
| 5 | Drive type | Automatic, with manual winding capability |
| 6 | Jewels | 4R35: 23 jewels 4R36, 4R37, 4R38, 4R39: 24 jewels |
| 7 | Magnetic field resistance | 4800 A/m (60 Gauss) |
Specifications are subject to change without prior notice for product improvement.
