Long turned parts

Long turned parts are slim, rotationally symmetrical precision components that are manufactured on so-called CNC sliding headstock automatic lathes. In contrast to short turning, Long turning, the workpiece is supported in a guide bush, which is only a few tenths of a millimeter away from the tool during machining.

This reduces the tendency to vibrate and enables precise machining of very long, thin workpieces. The process enables simultaneous machining with main and counter spindles, allowing milling, drilling, thread cutting and cross machining to be carried out in a single clamping operation. With multi-channel controls and tool-optimized cutting parameters, components with tolerances of up to ±0.01 mm and surface roughnesses of up to Ra 0.8 µm are created - ideal for high-precision series production.

Typical machines are Citizen A20, K16 or L20, which ensure continuous machining even with long runtimes thanks to automatic bar feeders.

Long turning covers a wide range of metallic and non-metallic materials.
Frequently used:

Automatic steels (e.g. 1.0718) - for economical series production with good chip formation
Quality steels and tool steels (e.g. 1.7225, 1. e.g. 1.7225, 1.3343) - for high-strength components with thermal stress
Stainless steels (e.g. 1.4301, 1.4404) - for corrosion-resistant applications in medical technology and fluid technology
Aluminum alloys (EN AW-6061, EN AW-7075) - for lightweight construction and e-mobility components
Non-ferrous metals (brass CuZn39Pb3, bronze, copper) - for electrical or precision components with plain bearings
Plastics (POM, PEEK, PTFE) - for non-conductive, chemically resistant precision parts

For special applications, nickel and titanium alloys (e.g. Inconel 718, Inconel 718, Inconel 718) are used. Inconel 718, titanium grade 5) are used for special applications.

Each material requires specific cutting data, rake angles, cooling strategies and tool geometries in order to maximize service life, dimensional stability and accuracy.

CNC sliding headstock turning allows very tight geometric and dimensional tolerances, even with long, slim workpieces.

With a temperature-stabilized production environment, ground clamping systems and digital measurement technology, we achieve:

• Dimensional tolerances of up to ± 0.01 mm
  
• Roundness accuracy of less than 0.01 mm
  
• Surface roughness up to Ra 0.8 µm (fine machining up to Ra 0.2 µm)
  
• Shape and position tolerances according to DIN ISO 1101
  
• Dimensional deviations according to DIN ISO 2768-fine
  

Thanks to inline measuring probes, optical SPC control and adaptive tool compensation, the values remain stable even with long series. For rotationally symmetrical micro-components, process monitoring in real time is also used to compensate for tool wear or dimensional drift.

Long turning is particularly efficient for small to large series where high repeat accuracy and minimal reworking are required.


Automatic bar feeding and multi-channel machining produce components with minimal non-productive times.

• Prototype production: for production-oriented design for later series production
  
• Small and medium series: with flexible tool configuration
  
• Large series: with robot-assisted unloading and automatic quality monitoring
  

Economical machining is primarily designed for diameters up to 20 mm and lengths up to 200 mm.

Typical applications include precision axles, bolts, sleeves, sensor mounts or valve components where high surface requirements and fitting dimensions are required.

Every long turned part undergoes multi-stage quality assurance, which takes effect during production. Testing is carried out inline and offline - automated and standard-compliant in accordance with ISO 9001 and IATF 16949.

Quality assurance includes:

• Dimensional inspection using tactile and optical measuring systems (e.g. Zeiss Contura 3D, Keyence optical scanner)
  
• Surface and roughness testing in accordance with ISO 4287 / ISO 13565
  
• Shape and position tolerances according to ISO 1101
  
• Hardness and microstructure testing for heat-treated materials
  
• SPC process data acquisition with automatic target/actual comparison
  

All measurement results are saved in the CAQ system and documented by batch.

On request, the customer receives test certificates in accordance with EN 10204-3.1 or initial sample test reports (EMPB) for series releases. This creates a completely digitally traceable production process that ensures traceability and auditability.

Long turning combines high precision, cost-effectiveness and process reliability - especially for slim, rotationally symmetrical components.
Compared to short turning or multi-spindle turning, it offers the following advantages:

• Guide bush principle: stable machining even with length-to-diameter ratios > 10:1
  
• Complete machining: Turning, milling, drilling, tapping and cross machining in one machine
  
• Reduced set-up times: Automated tool changes and bar feeding
  
• Higher dimensional accuracy thanks to constant clamping ratios
  
• Inline measuring systems for reproducible quality
  

This combination makes Swiss-type turning ideal for components with high surface requirements, tight tolerances and recurring series in industries such as automotive, medical technology and mechanical engineering.