Is Seiko Hardlex Crystal Better Than Other Watch Crystals?

When shopping for a new watch, you may come across the term “Hardlex crystal” and wonder what it is. In short, Hardlex crystal is a type of mineral glass that is used in the manufacture of many watches, including those from the well-known brand Seiko. In this article, we will take a closer look at Hardlex crystal and how it compares to other types of watch crystals.

What is Seiko Hardlex Crystal?

Hardlex crystal was developed by Seiko in the 1960s and is now used in a variety of their watches. It is made from a type of hardened mineral glass that is designed to be more scratch and shatter-resistant than standard mineral glass. Seiko uses this type of crystal in its watches because it offers a clear view of the dial, and it is also durable.

One of the main benefits of using Hardlex crystal is that it is less likely to scratch than other materials. It is also less likely to shatter if dropped, making it a good choice for an everyday watch. However, Hardlex crystal is not completely shatterproof and may still break if dropped from a high enough height or onto a hard surface.

How Does Seiko Hardlex Crystal Compare to Other Materials?

Seiko’s Hardlex crystal is comparable to other types of crystals used in watches, such as sapphire crystal and mineral crystal. Let’s look at these properties to see how Hardlex crystal compares with other dial materials.

Hardlex Crystal vs Sapphire Crystal

When looking at crystals, it’s common for watchmakers and collectors to rely on the universal scale of hardness to determine just how tough a material is. In the case of sapphire crystal, there’s only one other substance that outperforms it, and that’s diamond. That’s exactly the reason why many watchmakers use sapphire crystals in their timepieces due to their durability and scratch-resistance. However, that doesn’t mean it won’t easily shatter. This is because scratch resistance and shatter resistance are two very different things.

When compared to sapphire, Hardlex crystals are considered inferior in terms of scratch resistance. However, when subjected to strong impact, even the strongest sapphire will more likely shatter compared to a watch with a Hardlex crystal. This is because Hardlex possesses shatter resistance that not even sapphire could imitate.

Hardlex Crystal vs Acrylic

Hardlex crystals are made from a synthetic material that is a product of the fusion between alumina and silica. In terms of hardness, it’s nowhere near as tough as sapphire, but it’s definitely more scratch-resistant than acrylic, which is commonly used in vintage watches.

When compared to Hardlex crystals, acrylic is more susceptible to scratches. Acrylic is also softer than Hardlex crystals and is more likely to shatter when hit with a strong impact.

Hardlex Crystals vs Mineral Glass

Mineral glass is a type of glass that is made from natural minerals. It’s a great alternative to acrylic crystals and is often used in watches that are made with a vintage design. Although mineral glass is more scratch-resistant than acrylic crystals, it’s still less durable than Hardlex crystals.

When compared to Hardlex crystals, mineral glass is more likely to shatter or crack when hit with a hard object or when subjected to a strong impact. However, it’s still more scratch-resistant than Hardlex crystals and is often used in watches that are made with a vintage design.


In conclusion, Seiko Hardlex crystal is a high-quality, durable material that is scratch and shatter-resistant. It is a great choice for a watch crystal and compares favourably to other materials such as sapphire and mineral crystal.

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