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FAST FULFILLMENT & SAFE PACKAGING | LEARN MOREHardlex Crystal vs Other Crystals: How Does It Measure Up?

Seiko is famous for its durable and high-quality timepieces at affordable prices, and one of its most famous inventions is the brand’s patented Hardlex crystal. This proprietary glass material is present in many of Seiko’s entry-level watches. Many high-quality models boast this piece of protection, such as the Seiko 5 SNKL 48, the Turtle PADI, and the Alpinist.
Although Hardlex is by no means a substandard glass material, some people prefer to replace it with other types. But how does it measure up to other crystals? Let’s find out!
Seiko’s Hardlex Crystal: A Brief Overview
Hardlex crystal is one of Seiko’s proprietary glass materials, and they trademarked this invention around the early 1980s. It’s a mixture of barium and silicon, and Seiko reports that it is more scratch-resistant than traditional mineral glass.
Seiko makes Hardlex by tempering mineral glass in immense heat then chemically treating it, making it more durable and resistant to cracks, shatters, and scratches. Many of Seiko’s entry-level and affordable watches are outfitted with this crystal, and some may also have an anti-reflective coating to enhance legibility and reduce glare.
Now that we’ve covered the essentials of Hardlex, let’s see how it compares to other crystals available in the market.
Hardlex and Mineral Crystals
The majority of entry-level timepieces in the market have mineral crystals protecting their dials. This material is fairly durable, offering a clear and tidy-looking lens that you can polish to remove minor scratches.
Seiko claims that Hardlex is more scratch- and shatter-resistant than mineral glass, although demonstrations on their comparison have been scarce. Still, many enthusiasts report that Hardlex is a step above mineral and below sapphire.
Hardlex and Acrylic Crystals
Not many quality timepieces sport acrylic crystal or plexiglass nowadays because it’s notoriously weak and problematic. It’s a cheap plastic-based material that’s easy to produce and replace. However, some high-end pieces like the Rolex Datejust have acrylic on their cases. In many ways, Hardlex outclasses it due to its many weaknesses.
Hardlex and Sapphire Crystals
Many high-end watches use sapphire crystals to protect their dials because it scores a hardness level of 9 on the Mohs scale. It’s only one step below diamond, making it virtually scratch-proof. However, it’s more brittle than Hardlex and is less resistant to powerful blows. Because of this, Hardlex is more apt for tool watches for those who love a good adventure.
Sapphire crystal is highly reflective, so manufacturers often have to apply an anti-reflective coating to the material. As a result, it’s significantly more expensive than Hardlex, making it harder to replace.
Hardlex and Sapphlex Crystals
Another one of Seiko’s proprietary glass materials, Sapphlex is a mineral-based crystal coated in sapphire. It gets the best of both worlds—resistance against shatters and scratches. However, it’s also pricier than Hardlex.
Get Quality Seiko Mod Parts from the UK
Hardlex is a fairly affordable glass material that offers considerable shatter and scratch resistance. It’s an excellent choice for those who are on a tight budget and need clear and durable protection for their watch dials. However, if you’re looking for superior scratch resistance, you may want to opt for sapphire or Sapphlex.
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