Choosing Swiss screw machining vs CNC turning starts with the drawing. A small diameter makes a part worth reviewing for Swiss machining, but it does not decide the route by itself. Workpiece support, slender features, material, finishing and repeat demand all belong in the decision. For small precision turned parts, the useful question is how the part will be supported while its critical features are cut.
Ask for a process review of the complete finished part. Swiss-type support can help with slender turned geometry; compact, stiff parts may suit conventional turning. Compare quotations against the same drawing revision, material condition, finishing state, quantities and inspection requirements.
01
What is Swiss screw machining?
Modern Swiss screw machining uses CNC Swiss-type lathes, also described as sliding-headstock machines. STAR explains the supporting principle: the headstock moves the bar axially, and a guide bush supports the material near the cutting tool. Shortening the unsupported span helps limit bending during cutting, especially when a part is long relative to its diameter.
On a conventional CNC lathe, the usual starting arrangement holds the workpiece in a chuck or collet while the tool moves along it. Additional support may be appropriate for slender work. Both routes use CNC control; the comparison concerns machine layout and workholding, rather than whether the machine is computer controlled.
Swiss-machine support configurations also vary. Citizen documents guide-bushing and guide-bushing-less modes on its L32 platform. A process review needs to identify the proposed machine and configuration for the drawing, rather than assume every Swiss-type machine has the same setup options.
02
Why choose Swiss screw machining for slender parts?
Review the length exposed to cutting forces, rather than overall length alone. A stepped shaft may have a stout holding section and a slender working end. A sleeve may lose stiffness as its bore is opened. The support available at each operation matters more than a general label such as “micro part.”
Guide pins, contact pins, spring-probe plungers and barrels, fiber ferrule holders and sleeves, and small shafts or sleeves are part types OUJI has made. Their drawings can raise different questions about support, edge condition, bores and handling. Similar part names do not establish identical machining requirements.
Mark the functional interfaces: the locating diameter, sliding surface, mating bore or contact area. Explain how the component is used, and identify burr-sensitive edges. This gives a supplier something concrete to review before proposing workholding and an inspection method.
03
When conventional CNC turning remains a good candidate
A short, rigid part with accessible features may be straightforward to hold conventionally. Its small diameter alone does not make Swiss machining the preferred route. Conversely, a part that looks simple can demand careful support when a thin wall or slender section appears later in the sequence.
Avoid assuming that one process is always cheaper, faster or more accurate. Ask what the quotation includes: preparation, machining, finishing, inspection and handling. A useful comparison keeps the delivered requirement constant and lets the supplier explain the proposed route.
When requesting quotes from a precision turned parts supplier, ask which feature drives the workholding decision. Check that each quote uses the same material condition and acceptance state. Record any process assumptions alongside the quote, so a later drawing revision can be reviewed against them. This makes the comparison useful beyond the initial unit price.
04
Match the process to production demand and evidence
Repeat demand changes how preparation effort is shared across the order. At OUJI, production batches start at 1,000 pieces and samples start at 100 pieces. State the sample requirement, first production batch and annual volume separately. An annual forecast is planning information, not a commitment to a delivery schedule.
The published C3604 brass case covers 200,000 parts, while the SUS420J2 case documents a thin-wall component. Their published drawings, inspection records and production context help you identify which requirements are relevant to your own component.
Material and finish also belong in the comparison. Specify the grade and condition, and identify dimensions accepted after finishing. OUJI uses KEYENCE optical measurement; the drawing determines which features and report requirements need review. Gold over nickel plating is available, with the required finish specified in the enquiry.
05
Send a drawing for process selection
OUJI focuses on Ø0.1–10 mm turned parts. Ø0.1 mm minimum diameter — feasibility depends on part length, material and features. Include the full geometry so that a small diameter is reviewed in context, rather than treated as an isolated capability promise.
Provide a dimensioned drawing with its revision and a model if available. Identify fits, datums, threads, surface requirements and the final inspection state. If a feature is intentionally flexible or lightly supported, explain its function. State which requirements are fixed and which you want reviewed.
See the Swiss screw machining capability page, review materials and plating, then send your drawing and annual volume. Our photographed Swiss machining process shows the existing workshop sequence behind the service.
Sources & technical references
- Swiss-type CNC automatic lathe: guide-bush and sliding-headstock explanation — Star Micronics
The technical definition on page two supports the general process explanation. OUJI part requirements are reviewed from the drawing.
- Cincom L32: guide-bushing and guide-bushing-less configurations — Citizen Machinery
Manufacturer reference for configuration choices. The proposed machine and actual setup are reviewed against the drawing.
- OUJI Swiss screw machining capability and enquiry requirements — OUJI
Source for the published diameter qualification, batch quantities, part types, plating and measurement statements.
- C3604 brass production case — OUJI
Project-specific source for the 200,000-part quantity.
- SUS420J2 thin-wall production case — OUJI
Published component example; no tolerance or cycle figure is generalized in this article.
