Frequently asked questions

Servicing my watch

Where can I take my UNION GLASHÜTTE watch to have it serviced?

Take your Union Glashütte watch to a Union Glashütte retailer, who will ensure that your watch is serviced or repaired professionally in an authorised service centre by trained watchmakers. You can also take your watch to your jeweller of choice for forwarding to Union Glashütte.

What are the scheduled service intervals for my UNION GLASHÜTTE watch?

Take your Union Glashütte watch to a Union Glashütte retailer, who will ensure that your watch is serviced or repaired professionally in an authorised service centre by trained watchmakers. You can also take your watch to your jeweller of choice for forwarding to Union Glashütte.

Does my mechanical UNION GLASHÜTTE watch need to be serviced even if I don't wear it all the time?

Even if you do not wear your Union Glashütte watch all the time, the oils and greases it contains can evaporate or polymerise and degrade the rate accuracy of the watch.

We therefore recommend that you send your watch in to customer service every four to five years, regardless of how often you wear it.

Why don't you supply spare parts directly to customers?

Our customer service centres carry out servicing work to our high quality standards. As all customers have access to these authorised service centres, we do not supply spare parts directly to our customers.

How much does it cost to have my UNION GLASHÜTTE watch serviced?

The prices charged by the Union Uhrenfabrik GmbH Glashütte service centre in Germany can be found in the watch servicing price list. As many countries do not permit retail prices to be set, these are not binding.

Each independent, authorised Union Glashütte service centre can set their own service prices. Please use the contact data at Find certified service center, to ask for local watch service prices.

However, the recommended retail prices on the website apply in countries with an official service centre belonging to the Swatch Group.

What is the difference between a partial service and a full service?

For mechanical watches, a partial service consists of rate calibration. This service also covers the replacement of individual parts needed for water resistance. A full service is carried out if work is needed on the movement (replacement of worn components and oils). The full service also covers all the processes carried out in the partial service.

Temperature fluctuations

Avoid exposing your watch to extreme temperatures above 60° C or below 0° C or sudden temperature changes (e.g. in a sauna or plunging it into cold water after exposure to strong sunlight).

Why is it so important that my UNION GLASHÜTTE watch is serviced regulary?

Unlike many other mechanical instruments, your watch works non-stop, 24 hours a day, 365 days a year. To ensure constant accuracy, the individual components in the movement must be well-oiled and spotlessly clean. The quality of the oil degrades with time, causing slight friction and deposits which can have a negative effect on the accuracy of your watch.

Therefore, Union Glashütte recommends having your watch serviced regularly, every four to five years, so that the oil and worn components can be cleaned and replaced. To ensure that the work meets our quality standards, it is important that the maintenance service is performed by a watchmaker certified by Union Glashütte.

Setting of the watch winder

To ensure optimal winding, we recommend setting a watch winder to approx. 800-1000 revolutions per day. Please note the following recommendations for the direction of rotation of the watch winder:

Calibre U 289x and UNG-07.01: both sides.

Calibre 775x, UNG-25.xx and UNG-27.xx: one-sided, counter-clockwise.

Hand-wound watches are unsuitable for watch winders.

Please note that even when using a watch winder, wear and tear occurs in the movement and therefore a revision is recommended every 4 to 5 years.

To what depth are UNION GLASHÜTTE watches water resistant?

All UNION GLASHÜTTE men's watches are water-resistant up to a pressure of 10 bar (equivalent to immersing the watch in a depth of 100 metres). The ladies' watches are water-resistant up to a pressure of 5 bar (50m). All watches made of gold are water-resistant up to a pressure of 3 bar (30 m). All watches are tested according to the relevant ISO standards. 

Water resistance cannot be guaranteed indefinitely. It can be affected by ageing of the seals or by knocks to the crown or pushers. We therefore recommend that you have the watch checked for water resistance once a year by a recognised UNION GLASHÜTTE service agent and, if necessary, have defective parts replaced. Do not open the watch yourself under any circumstances.

Does UNION use scratch-resistant glas?

"Scratch-resistant" means that the material can "withstand scratches arising from normal everyday use".  Union uses sapphire crystal, which is characterised by high scratch resistance. However, if the sapphire crystal is affected by a material that is as hard as or harder than sapphire, scratches can still occur. Such material particles can be found in nail files, granite or sand.  We therefore recommend that you handle your watch with care and, if possible, do not wear it if you come into contact with other extremely hard materials.


Vermeiden Sie, Ihre Uhr extremen Temperaturen über 60° C oder unter 0° C auszusetzen, ebenso wie plötzliche Temperaturänderungen (z. B. Sauna oder Eintauchen in kaltes Wasser nach starker Sonneneinwirkung).

Wie hoch ist die Gangreserve meiner mechanischen UNION GLASHÜTTE Uhr und wie funktioniert der automatische Aufzug?

Die Armbewegungen des Trägers versetzen den Rotor in Bewegung, welche dadurch die Uhrenfeder aufzieht.
Eine voll aufgezogene Feder hält das Uhrwerk, je nach Modell, für ungefähr 60 h in Gang.
Da der automatische Aufzug direkt von der Aktivität des Trägers abhängig ist, reichen normalerweise 10-12 h Tragezeit pro Tag aus, um die Uhr für 20 h Gangreserve aufzuziehen. Somit ist sichergestellt, dass die Uhr über Nacht nicht stehen bleibt.
Falls die Uhr mehrere Tage nicht getragen wurde und deshalb stehen geblieben ist, kann sie mit ein paar Umdrehungen der Krone im Uhrzeigersinn wieder in Gang gesetzt werden.

Looking after my watch

Cleaning and care

Use a soft cloth to wipe your Union Glashütte watch clean of fingerprints and other forms of dirt. The watch and the stainless steel bracelet can be washed occasionally using warm, soapy water and a soft brush. Leather straps should never come into contact with water or soap, since this would shorten their service life.

Contact with cosmetics and chemicals

Avoid contact with solvents, detergents, perfumes or cosmetics. These are highly likely to impair the coating of the strap or case and damage the seals that keep your Union Glashütte watch water-resistant.

Physical impacts

In the event of a major, external impact, we recommend having your watch checked by a service centre authorised by Union Glashütte.

Handling your watch in water

Do not use the push-buttons in water. Even if your watch is water-resistant, it is extremely important that you do not press the push-buttons when the watch is in contact with water. If water penetrates, it could damage the movement. Also ensure that the crown is not pulled out.

Magnetic fields

As the majority of the individual parts are made of metal, magnetic fields could temporarily affect their function or even cause the movement to come to a complete stop. Therefore, we advise you not to place your watch on an electronic device or expose it to powerful magnets (e.g. refrigerator door, handbag clasp, etc.).


How long does a leather bracelet last?

Depending on the habits of the user, a leather strap should be replaced every 1-2 years. In general, watches with leather straps should not be worn for showering or swimming because this greatly reduces the life of a leather strap. Because leather straps are made of natural materials, moisture and dirt can be absorbed by the material. The lifespan is therefore strongly dependent on use.

Can I wear a stainless steel watch if I am allergic to nickel?

The materials we use for your UNION GLASHÜTTE watch are selected and tested according to strict criteria and fall below the legally specified limits for nickel tolerance. Nevertheless, we cannot definitively rule out the possibility that a small percentage of nickel-sensitised individuals may react even to our high-quality stainless steel. However, we can safely rule out the possibility of permanent nickel sensitisation. For more information about nickel permeability, may we ask you to contact our customer service directly.

What does PVD stand for?

PVD stands for "Physical Vapour Deposition". In the vacuum-based coating process, micro parts are applied to the product by ion bombardment or vapour deposition. They form a protective layer with a specific colour on the surface. In this way, very thin, flawlessly pure layers (1 μm) are achieved that are extremely hard and hypoallergenic.

What does DLC stand for?

DLC stands for "Diamond-Like Carbon" and refers to a special coating technology that is used for some Union Glashütte watches. This special coating gives the cases of our watches exceptional hardness and resistance to scratches and wear. The DLC process applies a wafer-thin layer of carbon-based material that not only preserves the timepieces' flawless lustre over a long period of time, but also emphasises their exceptional hardness, even under demanding conditions.


What does the SA behind UNION GLASHÜTTE/SA. mean?

The SA. stands for Saxony. In Germany, there are 32 places called Glashütte. The designation SA. after Glashütte thus makes it clear which Glashütte is meant.

Where can I get a UNION GLASHÜTTE catalogue?

Any official UNION GLASHÜTTE representative will be happy to give you a catalogue if you ask for one at a shop. You can also download it directly from our website. 


What is the power reserve of my mechanical UNION GLASHÜTTE watch and how does the automatic winding work?

The movements of the wearer's arm set the rotor in motion, which winds the mainspring. 

A fully wound mainspring keeps the movement running for about 60 hours, depending on the model.

Since automatic winding is directly dependent on the wearer's activity, 10-12 h of wear per day is normally sufficient to wind the watch for 20 h of power reserve. This ensures that the watch does not stop overnight.

If the watch has not been worn for several days and has therefore stopped, it can be started up again with a few clockwise turns of the crown.

What is the accuracy of my mechanical UNION GLASHÜTTE watch?

Mechanical watches without a chronometer certificate are adjusted by our watchmakers to a rate accuracy of between -2/+8 seconds per day. The accuracy depends very much on the individual habits of the wearer and can therefore vary. Contact your service centre to have the watch regulated accordingly.

What is the difference between a chronograph and a chronometer?

A chronograph is used to measure the time that has elapsed from a certain point in time. It is used to measure the duration of time at sporting events with the help of a chronograph hand and the minute and hour counters. A chronograph thus has two independent measuring systems: one for displaying time and one for measuring short periods of time. A chronometer is a highly accurate mechanical watch that has been awarded an official certificate by the Swiss Chronometer Testing Centre (COSC). Chronometer movements are subjected to accuracy checks and water resistance tests for 15 days and 15 nights in different positions and at different temperatures. To be entitled to bear the designation chronometer, the average accuracy of the mechanical movement must be - 4 / + 6 seconds per day. Thus, a chronograph can be a chronometer, but only if it is certified by the COSC. A quartz watch can also be a chronometer certified by the COSC. To do so, the movement must be equipped with an electronic system to compensate for variations in accuracy caused by temperature fluctuations. Quartz chronometers are tested for 11 days in one position and at three different temperatures. Quartz chronometers are up to 10 times more accurate than a standard quartz watch (± 0.07 seconds per day).

What is the difference between a hand-wound and an automatic movement?

Both movements are mechanical, but they are wound in different ways. Hand-wound watches must be wound by hand every day using the crown, while self-winding watches are wound using an internal rotor that responds to the movements of the wrist.

What is a tachymeter and how is it used?

On the watch, a tachymeter is used to measure the average speed over a certain distance. More precisely, it is a chronograph with a graduated scale on the dial or glass from which the speed can be read in kilometres per hour based on a distance of 1,000 metres. Only the central hand of the chronograph is used to read the tachymeter. Start the chronograph and stop it as soon as you have covered 1,000 metres. You can now read the speed on the dial using the central hand of the chronograph. Example of calculating the speed of a car: the chronograph shows that the distance of 1,000 metres has been covered in 30 seconds. The central chronograph hand indicates 120 on the tachymeter scale. The average speed over 1,000 metres is therefore 120 kilometres per hour.

Why is the roman numeral four shown as IIII if the correct numeral is IV?

Two spellings of the number 4 are permissible: IV and IIII. There are various historical explanations for this. It is known that IIII was used for four centuries to prevent confusion between IV and VI when the clock was upside down. Another theory is that in the 16th and 17th centuries IIII was used for the purpose of simplified reading for illiterate people. Ultimately, this spelling can also be seen simply as an aesthetic decision, since IIII forms a better harmony with the opposite VIII.

What is a pulsometer and how is it used?

A pulsometer is an integrated function of some of our watches, which makes it possible to determine the exact heart rate in a short time. This function is not only of interest for medical purposes, but also for athletes to determine the appropriate training intensity. Take your pulse and then press the chronograph. After exactly 30 heartbeats, stop the chronograph and you can then read off the pulse per minute using the external chronograph display.