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5 Legendary Tool Watches and the Man Responsible for Them

Helmut Sinn created the brand most associated with tough German watchmaking.

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Watch enthusiasts know the name Sinn as being more or less synonymous with tough German tool watches. Models like the U1 and the EZM series are recognizable to many, but less familiar is the man behind this celebrated brand.

Helmut Sinn, who passed away in 2018 at the age of 102, was an influential figure in watchmaking during the latter half of the 20th century, and his eponymous brand has made some of the toughest, most forward-thinking tool watches in the industry. Sinn was a former pilot who sought to form his own watchmaking brand during the 1960s. He aimed to produce high-quality watches that he could sell at a competitive price by cutting out the middleman and selling direct to consumers through catalogs. This is a business tactic associated with modern brands like Casper and Everlane, but in Sinn’s early years, it was incredibly novel.

Sinn’s specialty was tough and legible pilot’s chronographs, originally sold to the German military and police. Since its early days, it produced one of the first automatic watches that went into space, it reinvented the chronograph even and it helped get another brand — Bell & Ross — off the ground. Today, the brand is a pioneer in technologies that further the durability and legibility of mechanical timekeeping. Of course, none of this would have been possible without Helmut Sinn. The following timepieces are five of the brand's most important models, and they represent his legacy and brand vision.

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Jonas Ratermann

Heuer 1550 Bundeswehr


Yes, one of Sinn’s most iconic contributions to watch history was a Heuer. Originally made for the Bundeswehr, the German armed forces, the 1550 Bund featured a case made by Sinn. Sinn eventually took over the contract for servicing these watches in the 1980s, and so some can be found with newer Sinn-branded replacement dials. This arrangement eventually led to the Sinn 156, a continuation of the classic Bund chronograph, and later the 158.


Sinn 140


The Omega Speedmaster isn’t the only space chronograph. In 1985, German astronaut Reinhard Furrer went out and purchased a PVD 140 chronograph then wore it on the Spacelab D1 mission where it is said to have performed flawlessly. The watch featured a massive PVD-coated case and a Lemania 5100, considered one of the most durable chronograph movements ever made. Today the watch is still made but features a modified Valjoux 7750 as well as a stainless steel case hardened through the brand’s Tegiment technology.


Sinn 144


The 144 might be Sinn’s most recognizable design, produced, mostly unchanged, for decades. While the watch’s shrouded lug case design and info-packed dial make it stand out, the 144 is notable for helping launch another brand: Bell & Ross. During the early 1990s, Sinn produced watches to sell under the Bell & Ross name while the burgeoning watchmaker worked on its own original designs. The rebranded 144 GMT was one of those early watches that helped bring Bell & Ross into the mainstream.


Sinn EZM 1


In 1997, Sinn debuted one of its ultimate cult hits: the EZM 1.1 Mission Timer. Designed for the German military and first adopted by the Zentrale Unterstützungsgruppe Zoll (think of them as Germany’s SWAT), it featured a novel chronograph configuration where the subdials were axed in favor of chronograph seconds and minutes hand displayed on the main dial along with the running time, aiding in legibility. The watch was powered by a modified Lemania 5100 that was housed in a lightweight titanium case. In 2017, Sinn reissued this watch for its 20th anniversary.


Sinn U1


Sinn is best known for its chronographs but, in 2005, it made one helluva dive watch. The U1 was notable for eschewing traditional stainless steel for steel used in the making of submarines, which the brand maintains is more resistant to seawater than stainless steel normally used in watchmaking. The watch is still made today and boasts the same tough-as-nails case design and an impressive 1,000-meter depth rating. For those that prefer something smaller than the U1's 44mm case (and don't need a kilometer of water resistance), there's more recent 41mm U50.


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