Swiss Screw Machining Information
Image Credit: CM International Industries Corporation | Peridot Corporation | Alpha Omega Swiss, Inc.
Swiss screw machining services use Swiss screw machine equipment to produce turned parts with high-quality finishes that are comparable to ground finishes. They can also produce small-diameter parts with high-finish, close-tolerance bearing surfaces.
Swiss Screw Machining
A Swiss screw machine is an automatic lathe that has a sliding headstock and a guide bushing. The sliding headstock contains a collet which clamps and holds the bar stock (typically 12-foot metal or plastic bars) and rotates it (usually between 1000-10,000 RPM based upon the diameter and type of material). The cutting tools move in and out of the material to create required diameters while the headstock moves the material forward to create required lengths.
Swiss machines create the features of the part by moving the material and the tool at the same time. This is in contrast to other types of screw machines, which often form part shapes by using tools premade with built in specific shapes.
The material is then fed through a guide bushing, which is usually made of carbide. The bushing is adjusted for the material to slide through it, but tight enough to keep the material from flexing away from the cutting tool. The guide bushing allows Swiss-type screw machines to create fine surface finishes and hold very tight tolerances (+/- .0001") over long lengths in relation to part diameter. For example, a Swiss-type screw machine is necessary for turning a .100" diameter over a 3" length. The material would bend away from the cutting tool on a conventional lathe.
Swiss screw machine sliding headstock diagram. Image Credit: Iseli Company
Swiss screw machine shops typically indicate what materials they are capable of machining. It is important to find a shop with the proper material capabilities for the service required. Some materials commonly machined by Swiss screw machines include:
Nickel and nickel alloys
Steel and steel alloys
Swiss machine making small brass parts. Video Credit: Ganesh Machinery / CC BY 3.0
Swiss screw machine shops may offer a number of additional capabilities that correspond to the machining services they provide.
CAD / CAM support - Since most Swiss screw machines are automated by computer numeric control (CNC), machine shops often have the ability to take computer-model design files electronically and use them for part creation. Clients should consult the suppliers for details on the computer aided design (CAD) and computer aided manufacturing (CAM) software they use and support.
Design assistance - The supplier may offer assistance with concepts, manufacturing costs, manufacturing techniques, and material considerations. Suppliers may also be able to assist in upgrading or redesigning, re-evaluating or modernizing existing products to increase performance and/or reduce manufacturing costs.
Prototype services - Shops may provide services for building small quantities of representative parts for use in presentations and functional testing.
Low volume production - Shops may specify that they offer low volume production, meaning they can cost-effectively produce low quantities of parts for their clients.
High volume production - Shops may specify that they are capable of high volume production, meaning they are able to produce large quantities of parts in a reasonable time.
Reverse engineering - Some screw machine shops can offer reverse-engineering of parts in order to provide part replication or duplication services.
The costs associated with Swiss screw machining services, along with the shop's location, are important to consider in the selection process.
The service cost is important to consider in any application. Quotes (cost estimates) for part manufacturing orders are given to the customer after he or she provides the shop with the part specifications or a description of the requirements. Cost typically correlates to the time spent producing the product and the expense of the materials used (when purchased by the service company). Additional costs include transportation or shipment costs of the parts once they have been made.
Image Credit: Swissturn
The location of the shop is important to consider both for logistical reasons and expenses. Shops located farther away from the customer will have higher shipping costs, especially for high-volume production. In addition, there may be additional logistical complications when dealing with suppliers from different countries.
Swiss screw machines were originally designed for producing collets for watch balance springs. Today, they are used to manufacture mathematically precise parts for aerospace, defense, and electronics applications. Swiss screw machining services can also produce miniature screws, grommets and bobbins, contact pins for electronics components, and fasteners used in surgical and medical applications.