#7750

[every-tome]

[5sospicturesque]

Clearing out my camera roll 7750/?

[mrmikemichaelmichaels]

Lorsa Chronograph Valjoux 7750 #lorsa #Valjoux #7750 #chrono #Chronograph #watch #wristwatch #wristcheck https://www.instagram.com/p/CkEEqWzLyNp/?igshid=NGJjMDIxMWI=

[sidunawatch]

We took delivery this week of the first steel hands of our new project.

The arrow shaped tip is inspired by Engine Order Telegraphs, also called "chadburn", which were used on ships to communicate the desired speed to the engine room.

Tempered steel undergoes a heat treatment to make it more flexible and thus less prone to breaking under stress. This ancient metalsmithing technique was introduced in the manufacturing of tower clocks, portable clocks, pocket watches and wrist watches.

Today, steel tempering remains a prized finishing that gives the surface a deep blue. It is used for the steel parts of a watch such as the hands and the screws.

[sidunawatch]

In Spring 2021, we started working on a project that uses tempered steel hands. Their arrow-shaped design draws inspiration from steam engine telegraphs. Using modern day process, they are punched from a sheet of steel and subsequently given a curved surface under a hydraulic press. They are then tempered through a traditional process to achieve the desired hue.

The process of steel tempering consists of applying a heat treatment to ferrous metals such as iron or steel to increase their toughness, and paradoxically decreasing their hardness. Basically the steel is made mode ductile (more flexible), which inversely makes it less brittle and less prone to break under stress.

The technique predates watches by at least a millennium and the oldest know example of tempering is a steel axe from 1200 to 1100 BC found in Galilee. Tempering was known across Asia, Europe and Africa. It was introduced in clock making and made its way into portable clocks, pocket watches and ultimately, wristwatches.

The deep blue coating that tempering gives to steel hands and screws is a byproduct. The real purpose it to make them more flexible and less prone to breaking in case of shock or excessive force.

With the various technological advances made in metallurgy during the 19th and 20th century, newer and better steel alloys made it possible to circumvent the need for tempering. However, the trade is still taught in metal smithing workshops and watchmaking schools.

[sidunawatch]

The Valjoux 7750 was the first ever mechanical movement to be designed on a computer. The young watchmaker in charge, Edmond Capt, wanted to use Valjoux know-how to create a movement that would be straightforward to manufacture and to regulate. It is still in production after 47 years, and it has become a staple of Swiss watchmaking.

For our Siduna M3440 Compax and Fly-back chronographs, we use the Top Grade, which receives an Incabloc shock protection, a Glucydur balance wheel (same as the Chonometer Grade and more resilient to temperature change and shocks) and an Anchron Nivaflex NM hairspring. The bridges and rotor are decorated with Geneva stripes, which are designed to catch and hold specs of dust until the next servicing.

[sidunawatch]

The Fly-Back feature was perfected shortly before WWII by illustrious brands such as #Longines and #Hanhart, and quickly became popular with early military aviators. In 2018 we set on building one of the most sensibly priced Fly-Back chronographs, and it is now available with a black or tuxedo dial.

Image courtesy of worn&wound.

[dubbesworld]

We talk about chronographs. Listen to us talk about watches☝️link in bio #chronograph #caliber11 #elprimero #7750 #heuer #monaco #project99 #bondomega #artbydubbe (på/i Stockholm, Sweden) https://www.instagram.com/p/B9od5c3HykR/?igshid=1lgst1zavecv6