Stainless steel

The only grade of steel used by UNION GLASHÜTTE is 316L stainless steel. This alloy is characterised by its excellent anti-corrosion properties. The following components for the relevant watches are produced from this material: cases, bracelets, double-fold-fasteners with two push-buttons (decorated).


Refined gold is very soft and has the highest elongation at break of all metals. Soft, refined gold is a material that is ill-suited for use in jewellery, watches, coins, etc., and is therefore alloyed with other metals to alter its hardness, strength and colour, as well as to improve polishing results and bring down the price.

For its cases, crowns and pin buckles, UNION GLASHÜTTE only uses gold alloys with 750 parts per thousand of pure gold (18 carat).

  • Yellow gold is alloyed with copper and silver
  • Red gold is alloyed with copper
  • White gold is alloyed with palladium

PVD coating

PVD coating is the most advanced method of coating 316L stainless steel in the modern world. Not only does it permit gold plating, but it also allows other colours, such as black, to be applied. It is characterised by the following features in particular:

  • Coating hardness: 500–600 HV
  • Corrosion-resistance: Excellent resistance to exposure to the environment, salt water or human sweat.
  • Coating adhesion: Latest PVD process guarantees highly elegant aesthetics and good ageing properties.
  • Process temperature: Low-temperature coating process (100° C –360° C) prevents deformation of steel substrate metal.
  • Ecology: Process is 100% eco-friendly.

The term "physical vapour deposition" (PVD) denotes a vacuum-based coating process or thin-film technology in which the coating is built up directly by condensing a vapour consisting of the starting material.

The process used at UNION GLASHÜTTE, known as magnetron sputtering, is a combination of evaporation process and sputtering (cathode sputtering). It is used to coat the following components:

  • Hands and indices: PVD rose gold 5N (gold, copper, carbon, oxygen)
  • Cases and case components: PVD black (carbon, oxygen, titanium)
  • Double-fold fasteners and push-buttons


The sapphire used by UNION GLASHÜTTE for its crystals is a white, synthetic sapphire. Thanks to its hardness rating of 9, this crystal can only be scratched by very hard diamond-like substances.

UNION GLASHÜTTE watches use only double-sided anti-reflective sapphire crystals. As there are no reflections on the crystal, the full splendour of the dial can be revealed.


UNION GLASHÜTTE uses calfskin or goatskin straps, sometimes with a crocodile skin effect. Some ladies' watches have a synthetic satin strap, which is significantly more durable than a natural satin strap.

The four 'C's of a diamond

Cut The quality of the cut is often confused with the shape of the diamond. The cut is the only direct influence human beings have on the diamond. A good cutter can play with the shape and the quality of the cutting to improve the quality of the diamond. The cut will influence the fire and sparkle of the diamond. Created in 1900, the brilliant cut is the most used cut.

The brilliant cut consists of 57 or 58 facets (with or without culet). The cut required for stones which are to be set in watches is very demanding, as the diamonds are small and settings in stainless steel require a perfect cut. UNION GLASHÜTTE diamonds are cut in the traditional brilliant style, without a culet. The diamond certificate from UNION GLASHÜTTE contains the reference 32/24, where the total number of facets (top part to girdle/bottom part) is given, excluding the table.

Colour This means the intensity of a diamond's colour. The diamonds may be green, red, pink, blue and many other colours. The most common colours are brown and yellow.

The diamonds used in the watch industry are yellow. The scale of colour ranges from colourless to pale yellow with an infinite variety of subtle intermediate hues. The rarest of all diamond colours are white and colourless. So, the more colourless the diamond is, the more valuable it is. The colour of the diamonds used by UNION GLASHÜTTE comes under the Top Wesselton quality, as setting diamonds in white metals does not allow for any colour.

Many scales exist for the colour grading. The Wesselton scale is usually used for trade and the D to Z scale (by the GIA) is used as the official grading system.

The colour scale is broken down as follows:

Clarity This means the absence of inclusions in the diamond. Most diamonds have imperfections in them. The term „inclusions“ is used to describe interior and exterior imperfections. The clarity is determined by the amount of inclusions.

Carat  The carat is the standard unit of measure used to specify the weight of diamonds (and precious stones). One carat is equal to 1/5 gram (diamonds are also measured in points in the trade, that is to say 1 carat = 100 points).

All UNION GLASHÜTTE diamonds are “conflict free” and comply with the guidelines and certification system of the Kimberley Process. We are therefore able to provide the required written guarantee for each UNION GLASHÜTTE diamond: “The diamonds herein invoiced have been purchased from legitimate sources not involved in funding conflict and in compliance with United Nations resolutions. The seller hereby guarantees that these diamonds are conflict free, based on personal knowledge and/or written guarantees provided by the supplier of these diamonds.”

Water Resistance

All UNION GLASHÜTTE watches are water-resistant as follows:

Men‘s watches and the Seris Chronograph: Up to 10 bar (100 m).
Women‘s watches (with the exception of the Seris Chronograph):
Up to 5 bar (50 m).
Gold watches : 3 bar (30 m).

It should also be understood that water resistance cannot be guaranteed for an indefinite length of time. It may become compromised by an ageing of the seals or impact to the crown or pushbuttons. We therefore recommend that you have the water resistance of your watch checked once a year by an approved UNION GLASHÜTTE Service Centre and, if required, to have any defective parts replaced. Do not open the watch yourself under any circumstances.