Swiss machining is turning on a lathe whose headstock slides: the bar passes through a guide bushing, and the tools cut right next to that support, so a long, thin part does not flex under the cut. A machine built this way is called a Swiss-type lathe, a sliding-headstock lathe or, loosely, a Swiss screw machine.
This guide explains how a Swiss-type lathe works, how it differs from a conventional CNC lathe, where the design came from, what the terms mean and which builders make these machines. It ends with how to tell whether a lathe you own is a Swiss-type and what to note about it.
Machine Tool Exchange buys used Swiss-type lathes directly from the shops that own them, so the guide closes with the details an owner needs on hand.
What Is Swiss Machining?
Swiss machining is bar-fed turning in which the headstock moves the stock through a guide bushing. A collet in the headstock grips the bar, the headstock slides along the Z axis, and the bar emerges into the tooling area through the bushing. The cutting tools work at the bushing, where the bar is supported.
That arrangement is what separates a Swiss-type lathe from the other types of CNC machines. Today's Machining World, a trade magazine, said in 2009 that Swiss machines had always been preferred for long, slender turned parts and were by then widely used for small, complex parts.
How Does a Swiss-Type Lathe Work?
Today's Machining World describes the sequence this way:
- A collet grips the bar. Bar stock passes through a chucking collet in the headstock, which clamps onto it.
- The bar emerges through a guide bushing. The bushing locates the bar radially during machining.
- The headstock moves in Z. It moves precisely back and forth in the Z direction, taking the bar with it. The motion of the bar provides the feed for the cutting action.
- The tools cut next to the bushing. Turning tools carried on gang slides contact the bar very close to the guide bushing, usually within 1 mm to 3 mm.
The reason for the bushing is deflection. A workpiece held at one end bends under a side force, and the further the cut is from the support, the more it bends. Today's Machining World gives a rule of thumb for a conventional lathe: for a length-to-diameter ratio greater than 3:1, use a tailstock, and for a ratio greater than 6:1, use a steady rest or follow rest. On a Swiss machine, the article says, the guide bushing supports the workpiece so close to the tools that the deflection from cutting forces is essentially zero.
How Does a Swiss-Type Lathe Differ From a Conventional CNC Lathe?
| Feature | Conventional CNC lathe | Swiss-type lathe |
|---|---|---|
| Headstock | Fixed | Moves back and forth in Z, carrying the bar |
| Workpiece support | Held in a chuck or collet, sometimes with a tailstock or steady rest | Held in a collet in the headstock and supported by a guide bushing at the cut |
| Where the tool cuts | Anywhere along the part, often well away from the support | Very close to the guide bushing, usually within 1 mm to 3 mm |
| Number of axes | 2 to 5, per Fractory | 7 to 13, per Fractory |
| Bar size | Varies by machine | Generally limited to 2 mm to 38 mm, per Fractory |
Fractory's figures describe these machines in general. Any particular lathe has its own axis count and bar capacity, so read those off the model. To see how a conventional lathe is built and how it works, start with our guide to lathe parts and types.
What Do the Sub-Spindle, Gang Tools and Extra Axes Do?
Swiss-type lathes commonly add tooling around the cut. The sources we read describe these features:
- Gang slides. These carry holders for fixed single-point tools and may support live tooling.
- Sub-spindle. Fractory says most Swiss-style lathes today use one or two main spindles plus one or two secondary back spindles. The secondary spindle sits behind the part and generally picks it up as it is cut off, then performs secondary operations such as drilling or tapping the side of the part that could not be reached before parting.
- Back-working tool stations and turrets. Today's Machining World says many machines have back-working stations and sometimes one or more turrets that carry more tools.
- Live tooling. Today's Machining World says a Swiss machine can mill, drill, ream, saw and do other operations inside the machine, so a part can come off finished. Our page on multi-axis lathes explains how lathe axes, spindles and turrets are named and counted.
Where Did Swiss-Type Machines Come From?
The design comes from Switzerland's watchmaking industry. Today's Machining World says the collet chuck was patented in the 1870s, which allowed the use of bar stock, and that not long after, the first moving-headstock machine was developed in Switzerland. Those machines became known as Swiss-type screw machines and were used mainly in watchmaking.
Sources date the invention a few years apart. Wikipedia's article on the Swiss builder Tornos says its history goes back to 1880, when the first machines for making small watch parts were built in Moutier, and credits the Swiss lathe, called the Schweizer Drehbank, to Jakob Schweizer, dating his invention to 1880. Fractory dates the first Swiss-style lathe to the 1870s and also names Schweizer. The safe summary is the late 1800s.
From there, the story is one of automation and numerical control:
- 1905. The same Wikipedia article says the Mettetal/Junker Fils automatic sliding-headstock lathe, equipped with three tools, was launched.
- 1970. Wikipedia's article on Citizen Watch says Citizen developed its Cincom computer-numerically-controlled automatic lathe.
- 1970s. Today's Machining World says CNC versions of Swiss machines became available. Over time, it adds, tooling-area options came to include turrets and gang slides, live tooling and secondary spindles.
- 1978. Wikipedia's Tornos article says the company presented the Elector 16, its first numerically controlled automatic lathe with a sliding headstock.
- 1980s and 1990s. Today's Machining World says that by the 1980s Swiss machines were used extensively for semiconductor and electronics parts, and that improvements in design, servomotors and controls in the 1990s produced stronger and more sophisticated machines for medical and aerospace parts as well as general machining.
- 1990. Wikipedia's Citizen Watch article says the Cincom L20 was introduced.
Is a Swiss Screw Machine the Same as a Swiss-Type Lathe?
The names overlap, and they are used loosely. Wikipedia's article on automatic lathes says small to medium cam-operated automatic lathes are usually called screw machines or automatic screw machines, and that in shop-floor jargon the term "screw machine" by itself is still often understood to mean a mechanical screw machine. The same article says that in Swiss screw machining the workpiece is supported by a guide bushing near the cutting tool, and that some manufacturers, such as DMG Mori and Tsugami, market Swiss-type CNC lathes as "automatic."
The trade press uses the names together. Today's Machining World's own phrase for these machines is "CNC Swiss type automatic lathes (screw machines)." What defines the family is the sliding headstock working with a guide bushing. When a name is unclear, read the model plate and the builder's description of the machine.
Who Builds Swiss-Type Lathes?
Several builders list Swiss-type lines. This table shows what each builder's own pages or reference sources name, and it is not a ranking or a full list.
| Builder | What its pages name |
|---|---|
| Citizen | Cincom sliding-headstock lathes. Citizen's other principal brand, Miyano, is for fixed-headstock machines, per Wikipedia. |
| Tornos | EvoDECO, Swiss GT, SwissNano and Swiss DT, listed on its site under Swiss-type sliding-headstock lathes. Its MultiSwiss is listed separately, under multispindle machines. Tornos is based in Moutier, Switzerland. |
| Mazak | The SYNCREX series, listed under Swiss-type production turning machines, with maximum machining diameters in three bands: 10 mm to 12 mm, 20 mm to 25 mm and 32 mm to 38 mm. |
Wikipedia's automatic lathe article also names DMG Mori and Tsugami among the manufacturers that market Swiss-type CNC lathes as automatic, though we did not review their individual lines for this guide.
The brands that lead the listings on Machine Tool Exchange's Swiss-type lathe page are Citizen, Tsugami, Tornos and DMG MORI. For the machine type and what we buy, see our page on used Swiss-type lathes we buy. Our builder pages cover Citizen lathes, Tornos machines, Tsugami machines, DMG MORI Swiss-type lathes and the Mazak machines we buy.
How Can You Tell if Your Lathe Is a Swiss-Type?
Look for these features together, because no single one settles it:
- A headstock that moves along Z, carrying the bar.
- A guide bushing, or a guide-bushing adapter. Mazak, for one, describes a removable guide bushing adapter on its SYNCREX series that lets operators preset the bushing outside the machine.
- Gang slides of tools arranged close to the bushing.
- A bar feeder or bar loader, since Swiss-type machines are bar-fed.
- A sub-spindle behind the main spindle.
- A small bar or machining diameter in the model data, in the range Fractory describes.
Two cautions. Fractory notes that sliding-headstock CNC lathes are available that do not have a guide bushing, so the bushing alone is not the whole test. And a builder name alone does not settle it: Citizen, for example, makes both sliding-headstock Cincom machines and fixed-headstock Miyano machines. Check the model name against the builder's description of the machine.
What to Note on a Swiss-Type Lathe You Own
To describe a Swiss-type lathe accurately, collect these details from the machine:
- Model and serial number, from the data plate. A photo of the plate is more reliable than memory.
- Control name and software version.
- Maximum bar or machining diameter, as listed for the model.
- Configuration: number of axes, sub-spindle, live tooling, Y axis, back-working stations.
- Guide bushing set-up: the type of bushing and any adapter or spare bushings that go with it.
- Bar feeder, its make and model.
- Spindle hours, if the control displays them.
- Tooling and attachments that come with the machine.
These are the same things we look at when we buy a used Swiss-type lathe. Machine Tool Exchange buys them outright from the shops that own them and arranges the pickup. Request a quote or call 517-514-5190.
Frequently Asked Questions
What is the difference between a Swiss lathe and a regular CNC lathe?
On a Swiss lathe the headstock moves along Z and the bar passes through a guide bushing, so the tools cut close to the bushing, usually within 1 mm to 3 mm. On a conventional CNC lathe the headstock is fixed and the part is held in a chuck or collet, sometimes with a tailstock or steady rest.
Why is it called a Swiss-type lathe?
The design originated in Switzerland. Today's Machining World says the first moving-headstock machine was developed in Switzerland not long after the collet chuck was patented in the 1870s, and that these machines were used mainly in watchmaking.
Is a Swiss screw machine the same as a Swiss-type lathe?
The terms overlap. "Swiss screw machining" describes turning with a guide bushing near the cutting tool, which is what a Swiss-type lathe does. The plain term "screw machine" often means a cam-operated mechanical automatic, so check the model when the name is unclear.
What kinds of parts are made on a Swiss-type lathe?
Today's Machining World said in 2009 that Swiss machines had always been preferred for long, slender turned parts and were by then widely used for small, complex parts. Fractory lists watchmaking, aerospace, medical, electronics and automotive among the uses.
Does Machine Tool Exchange buy Swiss-type lathes?
Yes. Machine Tool Exchange buys used Swiss-type lathes directly from the shops that own them. We buy outright and arrange the pickup. Call 517-514-5190 or use the quote form on our sell page.
Have a Swiss-type lathe you want to sell? Machine Tool Exchange is a direct buyer, so the offer comes from the buyer. We buy outright and arrange the pickup. Get a quote or call 517-514-5190.