Watch crystal watch case and strap—materials in watchmaking.
From sapphire glass to nickel rules
A watch consists of far more materials than most people think about: the glass protecting the dial, the case housing the movement, and the strap or bracelet holding the watch in place. As a watchmaker, material knowledge is part of daily client advice—because the choice affects durability, price, appearance, and in some cases the customer's health.
§Watch crystal: three main types.
| Glass type | Property | Typical use |
|---|---|---|
| Mineral glass | Heat- or chemically treated glass, reasonably scratch resistant | Everyday watches in the mid-price range |
| Sapphire glass | Synthetic crystal, very hard and scratch-resistant, but can break with a hard blow | Quartz watches and diving watches |
| Plexiglas bends under impact instead of shattering and small scratches can often be polished away — a quality sapphire glass does not have. | Light plastic glass, bends on impact instead of breaking, scratches polish away easily | Vintage-inspired clocks |
The choice of glass is often a balance between price, scratch resistance and the ability to withstand a hard blow. Sapphire glass rarely scratches in everyday use, but can in rare cases shatter with a hard, sharp blow, while plexiglass instead bends and absorbs the impact.
§Watch case material.
- 01Stainless steel: durable, corrosion-resistant and relatively cheap to machine — the industry's most common choice
- 02Titanium: lighter than steel and often better tolerated by customers with skin sensitivity
- 03Gilt or coated metal: gives a gold look at a lower price but the coating can wear through over the years
- 04Solid gold: exclusive and heavy but softer and more sensitive to dents than steel
§Nickel allergy and legal requirements
The EU's REACH regulation contains a so-called nickel rule that limits how much nickel objects with prolonged skin contact may release—this applies, among other things, to watch cases, clasps, and bracelets. The rule exists to prevent contact dermatitis, and is particularly relevant when you work with cheaper alloys or older, gilded cases where the coating may be worn through. As a watchmaker, you should be able to advise a customer with known nickel allergy about which materials are gentlest.
§Straps and chains
- 01Leather strap: pleasant to wear, but absorbs moisture and sweat and needs to be replaced regularly
- 02Steel chain: durable against moisture and can usually be adjusted in length by the watchmaker
- 03Rubber/silicone: suitable for sports and leisure watches, handles water and sweat well
- 04NATO/fabric strap: robust, cheap and popular for everyday use, originally developed for military use
Material choice is rarely only a technical question. It is part of the trust the customer places in you as a professional that you can explain advantages and disadvantages in a language the customer understands — and that you choose solutions that suit both the watch's value and the customer's everyday life.