CNC turningSend your drawing or CAD model
CNC turned parts to drawing, up to Ø 230 mm
We turn precision parts on two CNC turning centres. Both have a turret with twelve driven tool stations, so holes, milled faces and threads are produced in the same setup as the turned profile. What we do not have is a sub-spindle: machining the back face means a second setup.
The two turning centres
| Machine | Axes | Capacity | Control | Equipment |
|---|---|---|---|---|
| DMG CTX 500 Beta | 4 axes | Ø 230 mm · spindle bore 67 mm | Heidenhain TurnPlus | Turret with 12 tool stations, all driven |
| Gildemeister CTX 410 | 3 axes | Ø 200 mm · spindle bore 55 mm | Siemens ShopTurn | Turret with 12 tool stations, all driven |
What we turn –
and where the limit is
The usable turning diameter ends at Ø 230 mm, the spindle bore at 67 mm. We machine bar stock up to that diameter. Larger blanks are cut beforehand on our CNC saw, which runs unattended up to 500 mm cutting width with an accuracy of 0.1 mm.
Two turning centres are not a high-volume turning shop. Our strength lies in turned parts that also have to be milled, EDM-machined, ground or documented – not in 50,000 simple bushings. If your part only needs turning and runs in high quantities, a dedicated turning shop is the more economical partner. We say so up front, not after the quotation.
Turned-milled parts
in one setup
All twelve tool stations on both turrets are driven. In the same setup as the turned profile we produce cross holes, pockets, wrench flats, slots, internal and external threads and off-centre hole patterns.
The real reason for a turned-milled part is not time saved but positional accuracy: the fewer setups a part needs, the more exactly the milled geometry sits relative to the turning axis. Milled geometries beyond what a turret can deliver are machined afterwards on our 5-axis centres.
What follows turning
All downstream steps are in house, with no transport between processes:
- Cylindrical grinding up to Ø 200 mm at 450 mm centre distance, for small parts up to Ø 50 mm at 200 mm – the route to tighter dimensional and roundness tolerances than turning alone delivers.
- Vibratory finishing for defined deburring of fine geometries.
- Sand blasting with corundum or glass beads.
- Ultrasonic cleaning for UHV and cleanroom-compatible components.
Materials
Bonsack specialises in difficult-to-machine alloys – titanium, Inconel, Hastelloy, Invar and Kovar. Which of them can be produced economically on our turning centres depends on the part: diameter, wall thickness, tolerance and batch size all matter. We clarify this in the feasibility check before a quotation is issued.
Proof instead of promises
The tolerance a turned part reaches depends on geometry, material and clamping situation – a blanket figure would be unserious. What is verifiable is the metrology: a Zeiss CONTURA G4 with scanning probe and a measuring uncertainty of 2.0 + L/350 µm, a Zeiss DURA MAX at 2.4 + L/300 µm with surface roughness measurement, a Keyence optical measuring projector and around 500 fit and thread gauges.
We define the tolerance concept together before production starts. That way it is settled before the first cut which dimension is checked how, and how it is documented.
We prepare a solid quotation with a realistic ramp-up
Frequently asked questions about CNC turning
What is the maximum diameter you can turn?
Ø 230 mm on the DMG CTX 500 Beta, Ø 200 mm on the Gildemeister CTX 410. The spindle bore is 67 and 55 mm respectively – that is the limit for bar stock fed through the spindle.
Do you machine bar stock?
Up to the spindle bore of 67 mm, yes. Larger blanks are cut beforehand on the Behringer HBP 313 A: up to 500 mm cutting width, accuracy 0.1 mm, and in automatic mode unattended for series parts.
Can you machine turned parts completely, including the back face?
Yes, but with a second setup – our turning centres have no sub-spindle. Where tight positional tolerances between front and back face are required, we tell you beforehand what is achievable and what is not.
What is a turned-milled part?
A component with a rotationally symmetrical basic shape and milled features – wrench flats, slots, cross holes, off-centre hole patterns. It is produced with driven tools in the same setup as the turned profile, which is why the milled geometry sits exactly relative to the turning axis.
Do you manufacture turned parts from a quantity of one?
Yes – single parts, prototypes and small series are our normal case. Conversely: for high quantities of simple turned parts with no milling, EDM or documentation content, we are not the most economical partner.
What tolerances are achievable in turning?
That depends on geometry, material, wall thickness and clamping situation – a blanket figure would be unserious. For tighter dimensional and roundness tolerances we grind cylindrically: up to Ø 200 mm at 450 mm centre distance. Inspection and documentation run on the Zeiss CONTURA G4 with a measuring uncertainty of 2.0 + L/350 µm.
Request a turned or turned-milled part
Send your drawing or CAD model.
We assess feasibility, name the limits and get back to you promptly.