Swiss Screw Machining
70 Tsugami Swiss lathes · screws, pins & micro parts · Ø1–20 mm · ±0.005 mm
CHX Metal provides Swiss screw machining on 70 Tsugami sliding-headstock lathes, producing screws, pins, bushings and micro components from Ø1-20 mm bar at ±0.005 mm. Threads are cut or rolled in-cycle, monthly capacity is 5 million pieces, and quotes return in 24 hours.
“Swiss screw machining” is the American term for what Europe calls sliding-headstock turning: parts machined from bar on a lathe where the guide bushing, not the chuck, does the holding. If your drawing is a screw, a pin, a ferrule or anything long and thin, this is the process that holds its tolerance — and the shop that runs it well is worth more than the shop that quotes it cheap.
What a Swiss screw machine actually solves
On a conventional lathe a long, thin part cantilevers out from the chuck and deflects under the cutting force. On a Swiss machine the bar slides through a guide bushing and the tool cuts within a millimetre of it, so the unsupported length is close to zero. That single difference is why screws, pins and medical shafts hold concentricity on a Swiss machine and go tapered on a conventional one.
| Specification | Capability |
|---|---|
| Bar capacity | Ø1–20 mm across the Tsugami cell |
| Typical L/D ratio | Up to 10:1 without secondary support |
| Tolerance | ±0.005 mm on critical diameters |
| Back-working | Sub-spindle + live tooling: threads, cross-holes, flats finished in-cycle |
| Monthly capacity | 5 million pieces plant-wide |
Threads: cut, rolled or milled
Thread strategy is where screw machining quotes diverge. Rolled threads are stronger and faster in volume but need stock allowance and a thread-safe diameter; single-point cut threads handle special pitches and blunt-start features; thread milling handles large diameters and interrupted cuts. Threads below M1.5 run on dedicated attachments rather than taps, because a broken tap costs the whole cycle at these sizes.
Tell the shop whether the thread is a fastening feature or a locating one. A locating thread can often be replaced by a press-fit and a cheaper process — but only if the DFM conversation happens before the price is fixed.
Materials that run well — and the ones that need care
- Brass C36000: the classic screw-machining stock — fast, clean threads, stable dimensions.
- 303 stainless: the stainless workhorse for screws and fittings; free-machining, welds poorly.
- 304/316 stainless: tougher and work-hardening; parameters matter more than speed.
- 6061 aluminium: light and quick, but gauge at 20 °C or the tolerance discussion is fictional.
- Titanium Gr5: runs cold and galls; coolant strategy and insert grade decide the finish.
- PEEK/POM: used for insulating screws and spacers; they move after machining, so finish cuts are light and staged.
Volume economics of screw machined parts
A Swiss cell amortises its setup over bar length, not over pieces, which is why unit prices fall steeply from prototype to volume. There is no MOQ gate: a single part and a 500,000-piece release run through the same process. What changes with volume is the inspection plan — first-article at low volume, in-process SPC at high volume.
Bar stock is priced by weight and copper alloys carry a moving surcharge. A quote should state its validity and its material basis; we name the LME copper basis on brass so the number can be checked rather than trusted.
Applications we run every week
Fasteners and custom screws, connector pins and ferrules, sensor and instrument shafts, medical instrument components, robotic joint pins, watch and optical parts, valve stems, threaded inserts for plastics, and RF contact components. The common thread is a rotating part that is longer, thinner or more precise than a conventional lathe wants to hold.
Related guides and capabilities
Swiss-type CNC machining in China · Swiss-type CNC turning · Sliding headstock turned parts · Custom CNC pins · CNC turned parts manufacturer · CNC machining capabilities
Request a quote
Send drawing (STEP / PDF / DXF) with material, tolerance and annual volume to mc@chxmetal.com. DFM feedback and a price within 24 hours, NDA on request.
Get a CNC quote · Contact CHX Metal · Supplier profile & certificates
Frequently asked questions
What is the difference between Swiss screw machining and CNC turning?
Swiss screw machining uses a guide bushing so the cut happens next to the support, holding tolerance on long, thin parts. Conventional turning holds the part in a chuck and cantilevers it, which suits shorter, larger parts.
What size range can you machine?
Bar from Ø1 mm to 20 mm on the Swiss cell, with chuck work to Ø300 mm on the CNC lathes. Length is limited by the bar feeder and the part geometry.
Can you thread M1 and smaller?
Yes, with dedicated threading attachments rather than taps at those sizes. Below M1.5 a broken tap costs the whole cycle, so the process is chosen deliberately.
What is the minimum order quantity?
One piece. Prototypes and production release run through the same Swiss cell; unit price steps down with volume as setup amortises.
How fast is a quote?
DFM feedback and price within 24 hours of receiving the drawing with material, tolerance and volume. Prototypes ship in 3–7 days.