Pins, contacts, valve spools and slender shafts from Ø0.5 to Ø25 mm, made on 80+ Swiss-type sliding-headstock lathes — Citizen, Tsugami, Star and Nomura. Send your drawing and an engineer reviews it before we price it.
Bar capacity (0.020″–0.98″)
Length-to-diameter, routine
Achievable on a held feature
Plus ISO 14001 & ISO 10012
Guide-bushing turning is the fastest and most accurate route for some parts, and the wrong choice for others. Answer three questions about your drawing and you’ll get our read — including when we’d point you at a different machine in our shop.
Our read
Swiss-Type Turning
A 3:1–8:1 body inside our bar range is squarely Swiss work — one setup, front and back features, no second op.
Send the DrawingThis is a first read, not a quote. Wall thickness, cross-hole position, thread class and tolerance stack all move the answer — which is why a person looks at every drawing before we price it.
Swiss machining is turning on a sliding-headstock lathe, where the bar stock moves axially through a guide bushing to the tool instead of the tool travelling to the bar. Because the cutting point sits roughly one diameter from rigid support, deflection and vibration nearly disappear — which is what lets a Ø2 mm shaft hold tenths over 40 mm of length.
Conventional lathes grip the bar in a collet and let it cantilever into the work zone. The further the tool travels from the collet, the more the part pushes away from the cut. On a Swiss machine the headstock advances the bar through a bushing mounted at the tool line, so the unsupported length never grows. The geometry is the whole argument.
The process came out of Swiss watchmaking in the nineteenth century, where it existed to produce screws and arbors nobody could hold any other way. Modern machines kept the bushing and added everything else: live tooling for cross-holes, slots, flats and knurls; a sub-spindle that takes the part off the main spindle and finishes the back face; multiple tool posts cutting at the same time; and bar feeders that let a cell run through the night unattended.
A guide bushing only earns its keep if there’s enough length to feed through it. On short parts — roughly under 2× diameter — the bushing consumes bar you’ve paid for and adds support the part doesn’t need. For those we remove it and run the machine in chucker mode: you keep the live tooling and the sub-spindle, you give up the slenderness advantage, and the bar-remnant loss drops. We decide which mode your part runs in at quoting, and it’s one of the reasons two similar-looking parts can price differently.
Check your largest turned diameter against the bar ranges below. If it falls outside them, the fixed-headstock and turn-mill cells at the bottom of the table pick up to Ø150 mm.
| Machine | Type | Units | Bar Capacity | Typical Work |
|---|---|---|---|---|
| Tsugami B206 / BO series | Sliding headstock | 48 | Ø1 – 20 mm | Connector pins, contacts, shafts |
| Citizen A20 | Sliding headstock | 15 | Ø0.5 – 25 mm | Valve spools, fittings, terminals |
| Star SR / SB series | Sliding headstock | 10 | Ø1 – 20 mm | High-feature multi-axis parts |
| Citizen A16 | Sliding headstock | 4 | Ø0.5 – 15 mm | Micro pins, sub-Ø3 mm work |
| Nomura NN-1085 | Sliding headstock | 4 | Ø1 – 6 mm | POGO pins, micro contacts |
| Citizen BNC 40# · Yangmu LM-06Y | Fixed headstock turn-mill | 6 | Ø5 – 150 mm | Short, large-diameter turned parts |
| Mazak Integrex-class turn-mill | Multi-tasking | 18 | to Ø150 mm | Valve bodies, complex prismatic-turned |
| Parameter | Metric | Imperial |
|---|---|---|
| Bar diameter | Ø0.5 – 25 mm | 0.020" – 0.98" |
| Max part length | 200 mm | 7.87" |
| Length-to-diameter | To 20:1 routine · 30:1 by review | |
| Achievable tolerance | ±0.005 mm | ±0.0002" |
| Production Cpk ≥ 1.33 | ±0.010 mm | ±0.0004" |
| Surface finish, as machined | Ra 0.4 – 0.8 µm | 16 – 32 µin |
| With honing / EP | Ra ≤ 0.2 µm | ≤ 8 µin |
| Axes | Up to 9-axis, twin tool posts, sub-spindle back working | |
| Monthly capacity | Up to 3 million turned parts, two shifts plus lights-out running | |
±0.005 mm is what we hold on a single controlled feature. ±0.010 mm at Cpk ≥ 1.33 is what arrives at your incoming inspection, lot after lot.
The gap between them is material behaviour, thermal drift across a shift, tool wear over a 5,000-piece run, and how many features share one datum. Both numbers are real; they answer different questions. If your print needs the tighter one on every dimension, tell us at RFQ — the answer is often a grinding or honing pass after the lathe, and planning it costs far less than discovering it at first article.
First articles in 5–8 working days from drawing approval. Production in 12–18 working days after FAI sign-off. Bar stock in exotic grades adds procurement time and we tell you that at quote, not at week three.
Material choice on a Swiss machine isn’t only about the part — it’s about how the bar behaves in the bushing over a 3-metre length. These are grades we run in production, with the parts they usually become.
The workhorse for fluid and medical work. 303 free-machining for high-feature parts, 316L where corrosion and biocompatibility matter. Typical parts: VCR and BA-grade fittings, diaphragm valve bodies, valve spools, nozzles, surgical instrument components, spinal and dental hardware.
The best-behaved material in a guide bushing and the cheapest per finished part. Typical parts: electrical terminals, contact carriers, lock components, pneumatic fittings, sensor bodies.
Where conductivity or spring temper drives the design. Tellurium copper machines cleanly at pin scale; beryllium copper gives contact force that survives cycling. Typical parts: POGO pin barrels and plungers, RF contacts, EV charging terminals, heat-exchanger inserts.
Chosen for weight, not machinability — long aluminium bars need care to stay straight through the bushing. Typical parts: standoffs, fuel-line fittings, antenna components, lightweight shafts.
Slow, hot and unforgiving of tool wear — which is exactly why the bushing helps, since it removes deflection from the variable list. Typical parts: bone screws, dental abutments, hydraulic fittings, aerospace fasteners.
Expensive bar, so remnant length matters more than cycle time. We plan part-off and bar-end strategy before we quote. Typical parts: high-temperature valve components, fuel system parts, downhole hardware.
Where hardness after heat treatment defines the part. Typical parts: pins, dowels, shafts, bushings, threaded studs, bearing races.
Dimensionally stable and cuts to a clean finish without melting at the bushing. Typical parts: insulator bodies, valve seats, gears, low-friction bushings.
Tough and chemically resistant; moisture uptake means we advise on stabilisation before tight-tolerance features. Typical parts: rollers, spacers, wear bushings, cable glands.
Where temperature, chemical exposure and sterilisation all apply at once. Typical parts: medical instrument components, semiconductor handling parts, insulating spacers, seal carriers.
Soft and creep-prone, so we adjust holding and inspection method rather than tolerance. Typical parts: seals, bearings, electrical insulators, chemical-line fittings.
Stiff, dimensionally stable at temperature, and transparent to RF. Typical parts: connector insulators, medical device housings, test fixtures.
These are the notes we end up writing back to engineers most often. Handling them at the drawing stage is free; handling them at first-article is not.
A guide bushing runs on the outside diameter of the raw bar. Standard cold-drawn stock has roundness and straightness variation that scores bushings and walks your finished diameter over a long run. Call out ground or precision-drawn bar — h9 or better — on anything holding tighter than ±0.02 mm. It costs a little more per kilo and removes an entire failure mode.
Live-tool features are strongest close to the bushing. A cross-hole 60 mm down an unsupported Ø4 mm shaft is a different operation from one at 6 mm — it may need a steady, a second op, or a redesign. If the position is functional, say so; if it’s arbitrary, moving it 20 mm toward the bushing can take real money out.
Rolled threads are faster, stronger in fatigue and produce no chip nest around a fine pitch. They need a controlled blank diameter and enough ductility, so they don’t suit every material or every class. Where the print allows either, tell us — on high-volume pins the difference shows up in the unit price.
Below about Ø1.5 mm, a burr is no longer something you remove afterwards — deburring media can bend the part. Burr control has to come from tool path, entry and exit geometry and part-off strategy. Adding a small chamfer or a relief groove at an intersection is usually cheaper than any downstream process.
Every bar ends in a stub that can’t be machined. On brass that stub is negligible. On Ti-6Al-4V or Inconel it becomes a visible line on your invoice. Part length that divides evenly into the bar, and a part-off allowance that isn’t more generous than it needs to be, both convert straight into material yield.
A drawing with ±0.01 mm on everything gets priced as though everything is critical. Mark the two or three features that carry function and open up the rest, and you will usually get a better price and a better part — because inspection effort concentrates where it changes something.
Swiss machining has a high setup cost and a very low cycle cost. Setting a multi-axis Swiss machine means building the tool layout, proving out front and back operations, aligning the bushing to the bar and running a first article — hours of work before a good part exists. Once it’s running, that same part may take twelve seconds.
That shape creates a breakpoint. Below roughly 1,000 pieces a year, setup dominates and you are often better served by a fixed-headstock turn-mill, where setup is shorter even though each part takes longer. Between 1,000 and 20,000, it depends on feature count — the more operations Swiss can collapse into one cycle, the earlier it wins. Above 20,000 there is rarely a competitive alternative.
We will tell you which side of that line your part falls on, including when the answer sends the job to a different machine in our shop, or to a process we don’t own. A quote that wins a job we shouldn’t have taken isn’t worth much to either of us.
Bar cost and remnant yield · number of live-tool operations · tolerance band and how many features share it · thread class and method · L/D and whether a steady is needed · inspection method and sampling plan.
Opening non-functional tolerances · moving a cross-hole toward the bushing · allowing rolled threads · consolidating two parts into one turned body · committing to an annual quantity with releases rather than one-off POs.
At 400,000 pieces a month, a 0.1% escape puts 400 defective parts on your line. Sampling alone can’t give you a number you’d be willing to defend to your own customer, so we don’t rely on it for critical features.
We run six CCD vision inspection and sorting machines (RKE RK-1500 and RK-2201, ±0.002 mm) dedicated to small turned parts. Critical outside diameters, lengths, chamfers and burr conditions are checked on every piece, not on a sample — the machine sorts, logs and separates. For connector and pin programmes this is the difference between a PPM number you quote and a PPM number you can defend.
Contact and terminal parts also go through insertion and withdrawal force testing (3× AISRY ASR-1021, 50 kg) so mating force is verified as a property, not inferred from geometry.
| Instrument | Model | Qty | Resolution |
|---|---|---|---|
| CMM | Mitutoyo 4078M-1211 | 1 | ±0.001 mm |
| Vision measuring | Rational CPJ-3025 | 3 | ±0.001 mm |
| 2.5D measuring | Rational CDP-1018 | 1 | ±0.001 mm |
| Optical comparator | Rational CDP-3015 | 4 | ±0.001 mm |
| CCD sorting | RKE RK-1500 / RK-2201 | 6 | ±0.002 mm |
| Surface roughness | Mitutoyo 178-560-01DC | 1 | Ra |
| Force testing | AISRY ASR-1021 | 3 | 50 kg |
| RoHS / XRF | SII SEA1000A | 1 | — |
| Salt spray, hardness and contour testing | 3 units | ||
A turned part is rarely finished when it comes off the lathe. These operations run inside our own facility under one control plan, so your part doesn’t wait in a queue at a third shop and there’s one team to call when something needs explaining.
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Five honing machines plus two extrude-hone systems — for bore geometry and for deburring cross-drilled intersections that no tool can physically reach.
A single-station EBW cell for narrow, low-distortion joints on assemblies that can’t tolerate heat input.
A dedicated EP line for ultra-high-purity and semiconductor fluid parts, where surface chemistry matters as much as roughness.
ASTM A967-type passivation for stainless, and anodising for aluminium parts that need wear or dielectric performance.
Electroless nickel, tin, gold and silver plating plus heat treatment, run on qualified partner lines under our control plan and our incoming inspection.
| Swiss-Type (Sliding Headstock) | CNC Turning (Fixed Headstock) | Turn-Mill / Multi-Tasking | |
|---|---|---|---|
| Workpiece support | Guide bushing at the tool line | Collet or chuck, cantilevered | Chuck, optional tailstock or steady |
| Best L/D | 4:1 to 20:1 | Under 4:1 | Under 6:1 |
| Diameter range | Ø0.5 – 25 mm | Ø5 – 150 mm | To Ø150 mm |
| Setup cost | High | Low | Medium to high |
| Cycle cost | Very low | Medium | Medium |
| Economic quantity | 1,000+ / year | 50 – 5,000 | 100 – 10,000 |
| Bar stock requirement | Ground or precision-drawn | Cold drawn acceptable | Bar or billet |
| Typical part | Pin, contact, spool, shaft | Bushing, adapter, hub | Valve body, manifold, housing |
Small-diameter turned parts with a high length-to-diameter ratio and a lot of features — connector pins and contacts, valve spools, bone screws, fuel injector components, sensor housings, precision shafts and specialty fasteners. Anywhere a part is long and thin relative to its diameter, or small enough that deflection would otherwise dominate the tolerance.
Support position. A conventional lathe grips the bar in a collet and the tool travels along an increasingly unsupported workpiece. A Swiss lathe feeds the bar through a guide bushing mounted right at the cutting line, so the unsupported length stays near one diameter regardless of part length. That’s why Swiss holds tolerance on slender parts a fixed-headstock lathe would push away from the tool.
We hold ±0.005 mm (±0.0002″) on a controlled feature, and ±0.010 mm (±0.0004″) across a production lot at Cpk ≥ 1.33. Surface finish comes off the machine at Ra 0.4–0.8 µm, and down to Ra 0.2 µm with honing or electropolishing. Which number applies to your print depends on how many features share a datum, material behaviour and lot size — we state it explicitly in the quote.
Ø0.5 mm (0.020″) on our Citizen A16 and A20 machines. Below about Ø1 mm, burr control, part handling and inspection method all become part of the design conversation rather than downstream steps, so send the drawing early.
As a rule of thumb, past about 4:1 a fixed-headstock lathe starts fighting deflection and chatter, and past 8:1 Swiss is usually the only sensible route. We run to 20:1 routinely and will review beyond that. Below 3:1 the guide bushing gains you little, and we’d generally quote the part on a turn-mill instead.
No hard minimum, but there is an economic one. Swiss setup is long and Swiss cycles are short, so below roughly 1,000 pieces a year setup cost dominates the unit price. For small quantities we’ll quote the part on fixed-headstock turn-mill as well and show you both numbers, so you can see what the setup is costing you at your volume.
Usually, yes — and it’s the single most common thing missing from drawings we receive. The guide bushing runs directly on the bar’s outside diameter, so roundness and straightness variation in standard cold-drawn stock will score the bushing and let your finished diameter drift over a run. For anything tighter than ±0.02 mm we specify ground or precision-drawn bar to h9 or better. It adds a little material cost and removes an entire category of failure.
Yes — Ti-6Al-4V and Grade 23 ELI, Inconel 718 and 625, Monel, Hastelloy, and PEEK in unfilled, glass-filled and carbon-filled forms. On expensive bar we plan part length and part-off allowance against material yield before quoting, because on superalloys the bar remnant is a real line item rather than a rounding error.
Material certificates traceable to the mill, dimensional inspection reports, FAI packages including AS9102 format, PPAP to the level you require, RoHS and REACH declarations, and plating or heat-treatment certificates. Inspection records are retained for three years and traceable to lot and machine. What ships with your parts is listed in the quote.
We sign your NDA — send it with the RFQ and it comes back executed. Drawings are not shared outside the engineering and production team handling your part, are never used in marketing without written permission, and are not shown to other customers. Partner finishing lines receive only the process requirement, not your full drawing package.
You get a DFM response with specific notes — bar spec, cross-hole position, tolerance stack — within one business day. Where the print is ambiguous you get a question, not an assumption baked into the price.
IATF 16949, AS9100D, ISO 14001 and ISO 10012 are audited annually by accredited bodies. Certificates available on request; on-site and remote audits welcome.
You talk to the same person from RFQ through production, in your timezone’s working hours, with the process engineer available on the call when the question is technical.
Turning, milling, grinding, honing, welding and finishing under one roof means one accountable party when something needs explaining — not a chain of subcontractors.
Traceability to lot and machine, three-year record retention, and change control that means the part you approve is the part that keeps arriving.
Export documentation, packaging validated for small precision parts, and delivery to North America, Europe and Australia. Packaging spec agreed before first shipment.
Upload a 2D print and a STEP file if you have one. You’ll get back a price, a lead time, and — where it matters — the specific notes that would make the part cheaper or more manufacturable. If the honest answer is that another process suits it better, that’s what you’ll hear.
