Staybrite

Staybrite was a trademark name for an alloy of stainless steel containing 18% chromium and 8% nickel, part of the SAE 304 stainless steel family. It was developed by Dr William Herbert Hatfield in 1924 in Sheffield England at the Firth Brown, it was offered to watchmakers by Acier Firth of Zurich starting in 1931.

The Staybrite name first appeared in advertisements in early 1926, with announcements of the new patented steel appearing worldwide, including in Geneva. Acier Firth in Zurich worked with Geneva case makers in 1931 to bring the alloy to the attention of watch and jewelry makers. The company advertised "Stainless", "Staybrite F.S.T.", and "Staybrite D.D.Q." steel in 10 varieties that year. The D.D.Q. version was aimed at watch case makers, protected by Swiss patent CH138647. D.D.Q. (for "deep drawing quality") was designed for good cold workability with 12.5% nickel, 12.5% chromium, and .05% carbon.

The first watch to be advertised with a Staybrite steel case was the Jaeger-LeCoultre Reverso: A 1932 advertisement claims "The completely non-oxidizable, non-magnetic and non-chrome "staybrite" steel housing is from the finest Geneva maker." The Jaeger-LeCoultre Duoplan was also advertised as using Staybrite in 1933. These would have been very early uses of the material, even before the trademark was registered in Switzerland in 1934, and they likely exposed the same weaknesses noted in contemporary laboratory tests in Geneva.

These case-making experiments were not immediately successful, with the tools formerly used to punch and stamp gold and brass proving too weak for stainless steel. The material also required multiple re-working passes with annealing and scouring in between, and each element had to be designed with the unique material in mind. It also proved impossible to solder Staybrite steel components together, much to the objection of case makers and jewelers. And a new process of polishing, burnishing, and buffing was needed to finalize the pieces, all being done by hand.

Professor Ph. Werner pressed forward with his work in Geneva, eventually demonstrating a working watch case making process in a 1933 lecture to the Society of Arts and Crafts. One of the first companies to offer Staybrite cases leveraging Werner's work was Vve. de Paul Bouvier of St-Ursanne, who may have been the supplier for LeCoultre's "Classic 3000" rectangular wristwatch, the first to specify Staybrite steel that same year. Robert Cart also advertised a new line of geometric pocket watches with Staybrite cases in 1934. The novel faceted straight-edge design was likely a result of the choice of Staybrite steel rather than the idea of a designer.

Staybrite was patented and vigorously protected by Firth through the 1930s. Prominent Swiss case makers offered Staybrite cases starting in 1935, including Junod & Fils, R. Raaflaub, Justin Gigon, G. Ruedin, Schmitz Frères, and La Centrale, with Bouvier continuing as a leader.

Prominent watch manufacturers using Staybrite in the 1940s included ARSA, Robert Cart, Ebel, Eterna, Glycine, Jaeger-LeCoultre, Lemania, Mido, Fabrique de Montilier, Omega, and Rolex. Staybrite was key to the marketing of the Jaeger-LeCoultre Reverso, Duoplan, and Classic 3000 in the 1930s, the sturdy Mido Multifort in 1935, the waterproof Omega Marine in 1936, the anti-magnetic and shock-proof Eterna Automatic in 1939, and even the Rolex Oyster in 1950.

Once the patent for the Staybrite alloy expired, SAE 304 stainless steel was widely produced and used in watchmaking. It remains popular to this day, and the Staybrite name is occasionally used to describe it, as Bulgari did in a 2011 advertisement for their Endurer Chronosprint. The Staybrite D.D.Q. alloy (with 12% chromium) is known for good cold workability, while the Staybrite 1.4435 W.C.Q. ("watch case quality") alloy is used for improved corrosion resistance, and the Staybrite 1.4435NCu has improved polish ability. Today Staybrite 1.4307 (known as 304L) is widely used in watches, with 1.4435 more popular in Switzerland and 1.4404 (316L) in Asia.

• Staybrite D.D.Q. "Deep Drawing Quality" - .05% C, 12.5% Cr, 12.5% Ni
• Staybrite 1.4307 "304L" - .02% C, 0.5% Si, 18.5% Cr, 19.0% Ni, 1.8% Mn
• Staybrite 1.4404 "316L" - .02% C, 0.5% Si, 17.0% Cr, 11.5% Ni, 2.3% Mo, 1.8% Mn
• Staybrite 1.4435 W.C.Q. "Watch Case Quality" - .02% C, 0.7% Si, 18.0% Cr, 13.0% Ni, 2.5% Mo, 1.0% Mn
• Staybrite 1.4435Ncu - .02% C, 0.12% N, 0.7% Si, 18.0% Cr, 13.0% Ni, 2.5% Mo, 1.3% Mn, 0.5% Cu