What metal should a watch be made from?
Posted on 19th July 2019 at 14:18
What are the main metals used to make watches? There is a lot of mystery around this to the end consumer so I thought I would enlighten everybody with a little bit more information.
For mainstream watches, there are predominantly two materials that are used, these are alloy and stainless steel.
Both have very different qualities, so I’ll explain a little bit further.
Base metal/alloy is mixed up different types of metal such as iron, copper, zinc, making it softer and also a lot cheaper.
Stainless Steel is also an alloy and carbon mixed with Iron is the main component. It is known for being a strong metal and also more stain resistant.
Alloy is cast, so a mould is made and pumped full of hot alloy and then cooled. The case moulds are broken away and then polished and finished to make the watch cases.
As with any metal, there are different grades of alloy, but most companies that manufacture watches in alloy use a standard basic alloy.
The negative with alloy is if you’re using a silver colour, you have to plate it, so long term there is a chance the silver plating well wear away. This will happen quicker depending on the type of plaiting that is used on the case.
Also, the finish isn’t as defined as what can be done on stainless steel. An easy way to explain this is to look at a brushed finish on the case. When an alloy case is finished in a brushed texture, it’s never as refined and detailed as what the stainless-steel brushed case would be.
An example of a brushed finish on alloy.
Stainless steel also comes in different grades however 316 stainless steel is higher quality and often used. Many companies that use 316 stainless steel promote the fact that it can be used for surgical equipment. The reality is this is purely marketing, and it is irrelevant whether the material your watch case is made from can be used to make surgical equipment as this has no bearing when used as a watch case !
An example of a stainless-steel brushed finish
Another benefit of stainless steel is the thickness of the case which can be cut thinner yet retaining a strong structure.
An example of this is on the shoulders, if the holes are drilled to close to the edge of the shoulders on alloy case, there is a chance over time, it will wear away and the pin will break through the shoulder. The pin must be drilled far enough away to prevent this from happening.
If the wall of the case is too thin, being a softer metal, it will buckle when the case back is pressed on.
The thickness of the case wall on an alloy watch must always be considered.
The hole can be drilled quite close to the edge of the shoulder on a stainless steel case without this concern. Square edges and cut detail can also be a lot more defined on stainless steel than it can on alloy.
One of the main features of stainless steel is it doesn’t need to be plated if you want a silver watch case.
As the metal itself is silver, there is no plating needed, resulting in the case staying silver for the life of the watch.
Another key benefit of stainless steel is how water resistant the watch can be made.
Alloy watches can be made to 5 meters water resistant (5ATM, 5 Atmospheres), but this is difficult to do, and there are lots of considerations, such as metal thickness and sealing of the case. It is easy with stainless steel watches to make them 5ATM.
If you want to go further and make the watch 10m water resistant, it has to be stainless steel.
Considerations such as a screw-on case back must be used.
Screw on casebacks can increase the level of water resitance
At this point though, I would like to highlight alloy is used for thousands of watches globally and is an excellent material. When designing a watch in an alloy, it is just using the limitations of the metal to get the best look. Make sure you consider the spec to ensure you don’t have any QC issues.
Brass is also used on watches but not as often.
Brass has some interesting properties. Brass is stronger than alloy but not as strong as stainless steel. It is also cast in the same way that alloy is but can be more refined as it is stronger. There is still a need for brass in today’s watch market.
If you want to make a watch that has fine detailing, and alloy isn’t strong enough (thin sections of metal in alloy would cause a problem and brake) brass is the perfect material in this situation.
It can be moulded into shapes that stainless steel can’t do. An example of this would be a more jewellery inspired watch bracelet with lots of cut through detailing and stone setting.
Brass can be used to make stronger detailed watch links.
The other two materials that are used for watches are precious metals, gold, and silver.
These materials have the same properties as if making jewellery when making watches.
Moulds have to be made, and the metal has to be cast and polished.
Silver and gold are a lot softer than the standard watch materials but using precious metals mean the watch will always have a value as the metal is a commodity.
There are also other materials used to make watches such as ceramic, stone, wood, but I will go into these further in detail in the future.
If this has been of interest or help, please feel free to leave a comment, and why not sign up to get useful updates directly.
I’ll be doing some more blogs soon with information about plating, leathers and other components that help make watches.
Thanks for reading.
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