Swiss Screw Machining

Precision miniature.
Long & slender.
±0.005 mm tolerance.

Swiss-type CNC turning for small-diameter precision parts. Sliding headstock provides bearing support next to the cutting action — enabling long slender parts impossible on conventional lathes. ±0.005 mm tolerance, Ra 0.2 µm finish, parts down to 0.3 mm diameter.

Swiss Screw Machining Quote CNC turning

0.3–32 mm dia ±0.005 mm Ra 0.2 µm Live tooling

01 · What it is

How Swiss Screw Machining works.

Swiss-type CNC turning uses a sliding headstock design where the workpiece moves longitudinally through a guide bushing while the tool is stationary. This design provides bearing support immediately adjacent to the cutting action, eliminating the deflection that occurs when turning long slender parts on a conventional lathe.

The original "Swiss" design emerged from the Swiss watchmaking industry — hence the name. Modern Swiss CNC adds live tooling (rotating tools that enable milling, drilling cross-holes, tapping), multiple turrets for simultaneous operations, and bar feeders for lights-out production of high-volume precision parts.

Result: precision parts with length-to-diameter ratios up to 20:1 (impossible on conventional lathes without tailstock support), tolerances to ±0.005 mm, surface finish Ra 0.2 µm, and part sizes as small as 0.3 mm diameter. The dominant process for medical implants, surgical instruments, watchmaking, and precision screw machine work.

02 · Specifications

Capability specs.

32 mm

Max bar diameter

Our Swiss lathe capacity. Bar stock up to 32 mm diameter fed from bar feeder

0.3 mm

Min diameter

Smallest practical diameter on our Swiss equipment. Below this, micro-machining territory

±0.005 mm

Tolerance

Standard precision tolerance. ±0.002 mm achievable on select features

Ra 0.2 µm

Surface finish

Single-pass finish on free-machining materials like C360 brass, 303 stainless

20:1

L/D ratio

Length-to-diameter ratio achievable — impossible on conventional lathes

Live tooling

Milling + drilling

Cross-holes, flats, milling features while part is turning. No second setup needed

Bar feeding

Lights-out

Automatic bar feeder enables unmanned production of high-volume precision parts

6,000 rpm

Main spindle

Typical main spindle speed. Sub-spindle for back-working without re-chucking

03 · Applications

Where Swiss Screw Machining excels.

Medical bone screws

Orthopedic surgical screws in Ti Gr.5 or 316L — ±0.005 mm thread precision

Dental implants

Dental implant screws in Ti Gr.4 — Swiss machining provides surface finish needed for osseointegration

Watch components

Horological pivots, arbors, balance staffs, escapement wheels — traditional Swiss application

Surgical instruments

Miniature surgical tools — forceps tips, micro-scissor blades, probe components

Precision shafts

Motor shafts, encoder shafts, precision mechanical shafts under 32 mm

Fiber optic ferrules

Ceramic and metal fiber-optic alignment hardware with sub-micron tolerance

Aerospace fasteners

Specialty aerospace screws per NAS/AS standards — titanium, Inconel

Electronic connectors

Precision pin hardware, miniature connector shells, IC socket pins

Automotive sensors

Small-diameter sensor bodies, thermocouple sheaths, ABS sensor components

04 · When not to use it

Not suitable for:

Every process has its limits. Being honest about where Swiss Screw Machining isn\'t the right answer saves time and money.

Parts larger than 32 mm diameter — use conventional turning or milling instead
Prismatic (non-cylindrical) parts — requires milling
Parts with L/D below 3:1 — conventional turning is cheaper
Very low volume (1–5 pieces) — setup cost per part may exceed conventional turning
Parts requiring complex 3D geometry beyond cross-axis features
Material thicker than 32 mm bar stock

FAQ

Swiss Screw Machining questions.

Conventional turning: part is held in chuck with free end extending unsupported (or supported by tailstock for long parts). Tool translates along part. Swiss turning: part passes through guide bushing with support immediately adjacent to cutting action. As cutting progresses, bar feeds through guide bushing. Result: deflection during cutting is essentially eliminated, enabling long slender parts with tight tolerances.

When all three apply: (1) part diameter under 32 mm, (2) length-to-diameter ratio above 3:1, (3) tolerance requirements below ±0.025 mm on critical features. For cylindrical parts meeting these criteria, Swiss typically wins on quality and cost. For parts outside these criteria, conventional turning or milling is appropriate.

Swiss machines have two spindles — main spindle holds the bar and does primary work, sub-spindle grips the finished part and enables back-side machining without re-chucking. Example: turn the OD profile on main spindle, cut off the part, sub-spindle grabs it, back-side features (facing, drilling, threading) machined. Eliminates secondary operations and tolerance stack-up.

Best: free-machining brass C360 (easiest, fastest), 303 stainless (free-machining), leaded steel 12L14, aluminum 2011 or 6061. Standard: 304/316L stainless, 4140 steel, titanium Gr.5, Inconel. Challenging but possible: PEEK, Vespel (harder plastic), hardened steel (pre-turned, harder to machine). Swiss handles virtually any CNC-compatible material; free-machining grades run fastest.

Swiss is most cost-effective for volumes above 100 pieces. Setup is time-consuming (programming, tool setting, bar feeder configuration) but once running, parts come off fast. High volume sweet spot: 500–10,000+ pieces per order. For low volume (below 50 pieces), conventional turning often cheaper. For extreme volume (100,000+), dedicated screw machines (cam-operated) may beat CNC Swiss economically.

Simple Swiss parts in common materials: 3–5 business days. Complex Swiss parts with live tooling features: 7–10 business days. Specialty materials (titanium, Inconel) add 2–5 days for material. Swiss production once running is very fast — primarily setup/programming time drives initial lead time.