A History of Precision: The Invention and Evolution of Swiss-Style Machining

[Editor’s Note: Longtime Modern Machine Shop contributor Barry Rogers, president of Illinois-based sales and marketing consultancy Alpha Strategies, died on May 18, 2024. Over the course of his long career in the machine tool industry, he worked for LK, Renishaw, Sunnen, Haas and Tornos, and had the opportunity to travel the world as a sales and marketing expert. In 2023, as a senior adviser to Tornos, he visited the Swiss machining pioneer’s headquarters in Moutier, Switzerland, and at the time of his death was putting the finishing touches on this article about the technology. We proudly publish this article — and the cover photo that particularly fascinated Rogers — as a memorial to a respected colleague, treasured mentor and valued asset to the world of manufacturing.

From the machine that brews the morning’s first cup of coffee and the high-end watch that adorns your wrist and conveys your status to your car’s turbocharger — or, if you’ve gone green, the connectors that make it possible to charge your electric vehicle — Swiss-machined parts are everywhere. And, thanks to Swiss machining’s ability to efficiently tackle highly sophisticated and difficult-to-machine materials like titanium and vacuum-arc-remelted stainless steel, it’s also a go-to solution for the manufacture of high-value medical products like bone screws, spinal hooks and dental implants.

Given its historic role in Switzerland’s watchmaking industry, where precision, quality and reliability are nonnegotiable, it should come as no surprise that Swiss machining today is manufacturers’ technology of choice when it comes to efficient and exceptionally precise serial production of the tiniest parts — some so small they are barely visible to the human eye.

Known by a range of names — automatic sliding-headstock lathes, screw machines, bar turning and automatic turning machines among them — Swiss machines these days are used to produce the most exacting parts for a vast range of industrial sectors, including automotive, micromechanics, electronics, medical and dental, and even luxury jewelry. Understanding how Swiss machining became an essential manufacturing technology requires a dive into both geography and history.

The Cradle of Two Industries

Switzerland’s “Watch Valley,” encompassing all the Swiss Jura Arc from Geneva to Basel, is the beating heart of the nation’s watchmaking industry, which took root in Geneva in the second half of the 16^th century. By the 17^th century, the industry had made its way over the Jura mountains to other regions.

The French-speaking Moutier district is the birthplace of Swiss machining, the technology that emerged more than 140 years ago to serve watchmaking. Around 1800, Moutier had the Jura Mountains’ smallest area of productive farm- and pastureland, and the growing Swiss watchmaking industry soon was providing farmers with a source of income beyond the soil itself. In 1849, the Moutier’s La Société Industrielle watchmaking factory was established in Moutier, eventually employing a quarter of the local population. Over time, other watchmaking factories were established in Moutier and the region.

The invention of the Swiss-type lathe — the original Swiss machine — is commonly attributed to Solothurn watchmaker Jakob Schweizer. In contrast to earlier technologies, Schweizer’s innovative bench-mounted Swiss-type lathe was fully automatic, including the supply of metal bars, and was capable of producing high-precision, complexly shaped parts of various sizes in large series. Tool movements were originally generated by cams on a camshaft that made a full turn to manufacture one part. First-generation Swiss-type lathes were mounted on a steel plate screwed directly down onto a workbench.

But it was engineer Nicolas Junker, one of the founding fathers of Moutier-based machine tool manufacturer Tornos, who had the expertise, entrepreneurship and foresight to take on manufacturing such machines on an industrial scale, modernizing and simplifying them, and optimizing their design. In 1883, Junker founded Junker & Cie in partnership with Anselme Marchal, owner of the Moutier glass and tile factory, and set up shop in La Glacerie, formerly the glass factory’s mirror production site.

In 1891, Junker introduced the first automatic lathe to the market. Five years later, in 1896, Junker filed a patent for “an automatic machine for the manufacture of shaped parts, such as screws, barrel shafts, etc.” Incidentally, the glass factory that eventually became Usine Junker today houses Tornos’ Le Deux Tour (The Two Towers) company restaurant and still features a testimony to Junker’s ingenuity: a water wheel that in its early days, using water from the nearby Birs river, generated hydraulic power through a central, ceiling-mounted axis and a series of belts to produce components for Junker’s early Swiss machines. That water wheel is still in operation and the system is now hydroelectric, producing 300,000 kWh of electricity per year — enough the power 60 four-person households.

Competing Moutier Machine Tool Makers

In 1904, Junker sold his company to his son Emile, who filed for bankruptcy in 1905. In 1906, local newspapers reported on the bankruptcy of Mettetal & Junker Fils which had been established by Emile Junker and Georges Mettetal in 1902; Junker Files & Cie and creditors were invited to convert their claims to shares.

However, it was in fact this bankruptcy that gave rise to Tornos. Beginning in 1904, mechanical technician and former Junker apprentice André Bechler devoted himself to the manufacture and development of the automatic lathe. With Joseph Pétermann and Jules Colomb, he established the Bechler & Cie partnership, which in 1912 became Bechler & Pétermann. In 1911, the La Glacerie premises were bought by a new company — Fabriques de Machines Moutier, Boy-de-la-Tour et Cie, anciennement Junker. Leaving Pétermann as the sole proprietor, Bechler departed Bechler & Cie in 1914 and set up his own business to continue his research and development of automobiles and side motors. In 1915, former Junker apprentice Henri Mancia joined Henri Boy-de-la-Tour et Cie. Joined by Willy Mégel, the company became Usines Tornos Fabrique de machines Moutier SA. In 1924, Bechler began manufacturing Bechler lathes after a 10-year absence from the machine tool industry.

In 1931, a new Bechler factory was built. In 1947, the business became the Fabrique de Machines André Bechler SA and operated under this name until the merger with Usine Tornos in 1974.

In 1981, the three companies Tornos, Bechler and Pétermann — which had been competitors until 1968 and 1974, respectively — merged under the new name Tornos-Bechler, Fabrique de machines Moutier. While the advent of electronics revolutionized the technologies and industrial structures, Tornos-Bechler Moutier became the main European manufacturer of Swiss-type automatic lathes.

Tornos’ enormous contribution to Moutier’s economy was underscored in the 1920s, when area watchmakers — desperate for high-precision screws — enlisted local farm women as contract machinists and provided them with sewing-machine-sized automatic lathes to get the jobs done.

Those looking for a deeper dive into the history of Moutier’s epic industrial history need look no further than the town’s Musée du tour automatique et d'histoire de Moutier. Lying in the heart of Moutier’s industrial zone, the museum traces the history of the legendary bar-turning machine from 1872 all the way through the present day. The museum, housed in Junker’s former mansion, showcases around 100 automatic lathes and is rich in documentation of Moutier’s industrial history.

A World of Firsts

Tornos’ development of thread whirling in the 1990s is just one example of how Swiss machining has continued to evolve. Thread whirling is similar to thread milling, except that the cutters are mounted on the inside of a cutting ring or cutting toolholder rather than the outside of a milling tool. In contrast to single-point threading, thread whirling offers several advantages, including the ability to more quickly machine, for example, the deep threads characteristic of bone screws. On Swiss-type machines, the thread whirling spindle works close to the guide bush to provide increased rigidity on screws with long length-to-diameter dimensions; the thread whirling process also affords faster setup because it eliminates the need to match rough and finished insert forms as well as the need for costly startup development costs and special support devices. Additionally, because thread whirling can be achieved in a single pass from bar stock, cycle time is reduced.

Other firsts include the 1930 introduction of the first mass-production Swiss-type lathe, the Tornos M10. In 1958, the first cam multispindle machine, the Tornos AS 14, was presented. Looking ahead to 1978, Tornos debuted its first T-type lathe with a numerical control, the Elector 16. In 1988, Tornos launched the CNC 632, the world’s first CNC multispindle machine. The 1996 launch of the Tornos DECO and MultiDECO concept marked a true revolution in the market and the start of a new era. More than 10,000 of these machines were installed globally and many of them are still running day and night.

Setting a Course for the Future

Today, modern Swiss-type lathes can churn out hundreds — or hundreds of thousands — of perfectly identical and precise parts with no human intervention. These wonders of parts production innovation offer faster production than standard lathes due to tooling placement and provide greater stability and versatility because they can be affordably adapted with specific toolholders for operations like polygon milling.

Additionally, Swiss-type lathes offer quicker ROI: This publication as well as sister brand Production Machining are filled with stories about shops that have achieved 10 to 15 times faster production speeds using Swiss-type machining compared to milling, along with better surface finish, less variation and dramatically reduced part costs due to the machines’ ability to run unattended overnight. 

All these benefits underscore the value Swiss machining — with its rich history and a trajectory toward the future — brings to manufacturers, whatever their industry, precision application or specific requirements, wherever they are in the world.