Grand Seiko’s Ever-Brilliant Steel is a highly durable watchmaking material made to last generations.

The idea for Ever-Brilliant Steel can be traced to the after-sales service department.

To create the world's finest wristwatch: This was the passion that drove the development of Grand Seiko, which was born in 1960. Since its first watch, Grand Seiko has pursued the values of accuracy, beauty, and legibility. Combining these qualities at a high level, Grand Seiko has produced numerous luxury timepieces that can be enjoyed for many years and are easy to use.

Grand Seiko achieves its noteworthy accuracy through high-performance movements that it develops and manufactures in-house. The beauty and legibility of Grand Seiko watches can largely be attributed to the influence of the Grand Seiko Style, a unique design language established with the introduction of the 44GS in 1967. The goal of that seminal creation was to create a "brilliant wristwatch.” Grand Seiko continues the legacy of the Grand Seiko Style and uses techniques such as Zaratsu polishing, in which the watch’s case is held against a rotating metal plate, as well as by adding a hairline finish, to create a beautiful luster.

Most high-end watches are made of stainless steel, a material with corrosion resistance and high workability that allow for it to be used in chemical equipment and to be polished to a beautiful finish. Though working with new materials can be a challenge, several brands have introduced stainless steel with higher performance attributes.

A typical example is 904L. A high-performance stainless steel with superior corrosion resistance and a white brilliance compared to lesser grades, 904L is generally used as an exterior material in high-end watches.

"In the after-sales servicing of wristwatches, we have seen some stainless steel case backs that have rusted and corroded, probably due to sweat and other factors,” said Yasunori Hara, Seiko Watch Corporation’s Exterior Design Engineering Department Manager. “Many people think that stainless steel does not rust; however, it is not ‘rustproof,’ only ‘rust-resistant.’ Depending on the environment in which it is handled, even stainless steel cannot avoid corrosion. Stainless steel still has room for further development. If a stable supply of 904L becomes available, many brands may eventually start using it. With this in mind, we launched a project to develop a new stainless steel alloy that would have superb anti-corrosive properties.”

“After more than three years of development, Ever-Brilliant Steel was born,” Hara continues. “The most remarkable feature of Ever-Brilliant Steel is its outstanding corrosion resistance. Stainless steel with a Pitting Resistance Equivalence Number (PREN) over 40 is classified as ‘super stainless steel’ in the steel industry. The super stainless steel that forms the foundation of Ever-Brilliant Steel demonstrates such high performance that it is used in ocean structures and chemical and food plants. It far surpasses the performance benchmarks of the stainless steel currently used in watches.”

One of the criteria for evaluating the corrosion resistance of stainless steel is the PREN mentioned above, which indicates the ability of stainless steel to resist corrosion in a chloride environment. Conventional stainless steel has a PREN of around 25, 904L has one of approximately 35, and Ever-Brilliant Steel used by Grand Seiko has a PREN over 40.

"The critical factor in our decision to introduce Ever-Brilliant Steel to Grand Seiko was its ability to ensure the same or better brilliance compared to conventional stainless steel when polished,” Hara continues. “The name speaks for itself. Ever-Brilliant Steel also has the great feature of protecting this beautiful shine from rust and maintaining it for a long time.”

Strong and beautiful Ever-Brilliant Steel

"When we decided to implement a new stainless steel alloy, we researched and evaluated a bunch of super stainless steels," says Hara.

When developing Ever-Brilliant Steel, the top priority was its high corrosion resistance. Another essential point was to ensure the aesthetics of the Grand Seiko watch. Decorative purposes are not the priority for super stainless steel, so aesthetics are not a consideration in general. It is acceptable if it meets performance standards, even if some impurities mix in. Grand Seiko’s non-negotiable conditions for the material were that it be able to achieve the desired aesthetics for the brand and that a stable supply of it could be created.

"As with 904L, super stainless steel is difficult to forge and cut,” Hara continues. “Therefore, better workability was also a condition for consideration. No matter how high-performance and beautiful it is, it is not very meaningful if one cannot mass-produce it."

Ultimately, through trial and error and the adjustment of metallurgical composition, the alloy that is Ever-Brilliant Steel was born.

Ever-Brilliant Steel is the ideal material for a watch worn daily.

"Conventional stainless steel also has excellent corrosion resistance, but even so, the case back, which is in contact with the skin for long periods, can still corrode in rare cases. The improved corrosion resistance is a significant advantage when considering the watch's longevity."

Although corrosion of the case back can be prevented through daily care, such as wiping the watch after removing it, it is not easy to do this every time a watch is worn. In addition, if a person's body is prone to sweat with chloride, the watch is more susceptible to corrosion. However, the corrosion resistance of Ever-Brilliant Steel is such that it is almost impossible for it to rust from daily use. On the other hand, another advantage of Ever-Brilliant Steel is that it is easy to use without worrying about daily care. This ease of use is one of the things that Grand Seiko sees as the essence of a wristwatch.

Grand Seiko now accepts repairs regardless of the year of manufacture. Such a watch brand is rare, even in Switzerland. It is possible because Grand Seiko aims to ensure that its timepieces can be used for a long time, as mentioned above. Ever-Brilliant Steel fulfills the manufacturer's wish to provide an accurate, beautiful, and easy-to-read watch that users can enjoy for many years.

From generation to generation, it will remain beautiful.

Ever-Brilliant Steel is far more corrosion-resistant than conventional stainless steel, but its hardness is almost identical. Scratch resistance is practically the same level, so it is not a maintenance-free or scratch-free material. Many brands will re-polish stainless steel cases and bracelets to remove minor scratches. Grand Seiko introduced a new exterior repair polishing service in Japan from 2021. They are equipped with a laser welding machine, and their service involves repairing stainless steel exteriors by melting a thin wire rod by laser and filling in deep scratches that cannot be erased by re-polishing.

"Ever-Brilliant Steel can also benefit from our exterior repair polish service,” says Hara. “However, laser welding can only fill scratches, regardless of the material. Pitting caused by corrosion cannot be welded".

This is because it is impossible to see how far the corrosion has deepened around the pits.

"We can now erase the scratches. If we can completely prevent corrosion, then watches can be used for longer. That is why we prioritized corrosion resistance in the development of Ever-Brilliant Steel".

Ever-Brilliant Steel can be repaired for years to come, and scratches can be erased from it. The development of Ever-Brilliant Steel, which is virtually corrosion-free in daily use, was not born out of the idea of “no maintenance.” Rather, it was developed based on the premise of after-sales service. Why is this so? Grand Seiko aims to create the ultimate wristwatch that can be an heirloom given, in beautiful condition, from parent to child to grandchild through the years, connecting the manufacturer and owner through appropriate after-sales service.