Swiss Screw Turning vs. Traditional CNC Machining

CNC Machining

The concept behind the lathe and its turning process has driven human innovation and craft since the minute handwork of ancient Egypt. These lathes served as essential hand-turned cutting tools, with workers producing parts from a piece of stock by cranking it around and around against a tool, allowing the lathe slowly cut into its circumference.

The basic mechanics of the original lathe have not changed. A material, typically some kind of bar stock, spins around its longitudinal center at high speeds. Cutting tools, knives, forms, and bits are then applied to the outside surface, removing material from the stock to shape a precise finished part. These tools are consistent and effective, producing refined work for both technical and decorative applications.

This versatile process creates many of today’s highly engineered metal and plastic parts. Turning and lathe-based machining supports industries of all kinds, from aerospace, commercial, and medical to electronics and military.

The Benefits of Turning Technology and CNC Machining

Today’s lathe technology has evolved into sophisticated turning systems with highly efficient, incredibly consistent operations and sophisticated features such as automatic operation and custom programming.

Computer numerical control (CNC) machines, in particular, are extremely popular due to their fast, efficient process. These tools operate based purely on digital controls. Once a program has been perfected, the machining can produce parts at high speeds, with the tightest possible tolerances, over and over again. The process is also cost-effective, quick, and extremely precise.

CNC machining equipment comes in a wide variety of styles, all optimized to suit unique jobs and create high-quality components. Vertical milling centers are the easiest of these machines to program, offering an efficient option for short-run parts. Horizontal milling centers operate at higher speeds, offering large volume orders with quick turnarounds and reliably high quality.

Industrial Swiss Screw Turning

Swiss screw turning, or Swiss screw machining, is misleadingly named; screws are in no way critical to operation. In fact, Swiss turning is nearly the same as standard CNC turning.

A Swiss screw machine turns parts much like any automated lathe, with a rapidly spinning bar stock and high-precision CNC or automatic electric control. However, Swiss tools operate with two essential differences.

  • Swiss guide bushing — The collet chuck of a Swiss screw machine incorporates a guide bushing, just at the opening that the bar stock feeds through. While this may not seem important, the bushing’s support minimizes any kind of wobbling in the bar caused by centrifugal force. The part maintains stability and allows for highly precise tolerances, even in tiny, long, and narrow applications.
  • Reduced cutting deflection — The cutting tools on Swiss machines contact the stock next to the guide bushing, offering even more stability. The bushing neutralizes the deflection caused by the force of a cut, while the tool maintains an even position in the rotating bar stock.

Overall, Swiss screw machines are built for perfect precision, even in the most delicate parts with the most demanding tolerances.

Choosing the Right Turning Process

The minimal workpiece bending that occurs in Swiss screw machining makes this manufacturing method ideal for high volumes of small, cylindrical pieces with extremely tight tolerances. Swiss-turned parts can be made from nearly any kind of metal, plastic, or high-performance engineering material.

CNC machines offer high repeatability, excellent precision, great versatility, and speed in manufacturing — all at very competitive prices. The Swiss build takes this technology one step further for tiny, delicate parts: A CNC Swiss screw machine rotates a part at up to 10,000 rpm with an accuracy of 0.0002 to 0.0005 inches.

Originally developed by Swiss watchmakers, today’s machines support prized parts in more than timepieces; critical aerospace components, implantable medical devices, and firing pins can all be cut with quick, unwavering precision.

The Value in Modern Turning Technology

As manufacturing technology continues to advance, the demands on components become increasingly stringent. CNC tools and Swiss screw machines can craft these precision parts with unparalleled speed and efficiency, serving some of the world’s most demanding industries and applications.



Image Credit: Andrey Armyagov/


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