Turned yellow part

CNC turning of plastics

Precision manufacturing of CNC-turned parts from Engineering Plastics

Plastic turning is a machining process used to manufacture precise, rotationally symmetrical components from engineering plastics. At Ensinger, we manufacture CNC-turned plastic parts from prototypes to series production and tailor tool geometry, cutting parameters, and clamping technology to your specific material. This is how we at Ensinger produce precise plastic components with consistent quality and surfaces optimised for their intended function.

Get quotes and order CNC turned parts

Ensinger offers maximum flexibility when ordering your CNC turned parts:
With our online platform TECAPART, you can quickly and reliably get quotes for your components and order them directly. 
  • Upload CAD data and drawings (STEP, PDF, DXF)
  • Have an automatic technical analysis performed
  • Receive a transparent quote
  • Have prototypes and production runs manufactured
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Alternatively, we are also available to assist you in person with complex components, special technical requirements, or material consulting. Through a personalised consultation, we will work with you to develop the right solution.
Customised quotes and consultation Order a CNC-machined part

What is CNC turning of plastic?

CNC turning of plastic is the machining of a rotating workpiece made of engineering plastic. In this process, specialised cutting tools remove material in a controlled manner to produce precise geometries and functional surfaces. Unlike metal machining, the machining of plastic requires a process design tailored to the material. Engineering plastics have lower thermal conductivity, higher thermal expansion, and often exhibit more elastic material behavior. Therefore, the machining strategy, tool selection, and heat management must be tailored to the material. Thanks to many years of experience with engineering and high-performance plastics, we at Ensinger ensure material-appropriate, precise, and reliable processing of every material used.
Turned blue part

What makes CNC turning of plastic unique?

CNC turning of plastic enables the production of precise and cost-effective components for many technical applications. This results in the following characteristics, among others:

  • High dimensional accuracy
  • Good surface quality
  • Reproducible manufacturing quality
  • Cost-effective production, from single parts to series production
  • Material-appropriate machining of engineering plastics
  • Combination with milling operations in a single setup

Plastic turning: Key process parameters and typical machining operations

Several process factors are crucial for achieving precise results when turning plastic parts. These include positively designed tool geometries, polished cutting surfaces, sufficiently large chip clearance zones, and a low-vibration, stress-free workpiece clamping system. Controlled heat management is equally important to minimise thermally induced dimensional changes. Typical machining steps include, for example:
  • External machining
  • Internal machining
  • Plan processing
  • Milling
  • Grooves and slots
  • Chamfering
  • Internal threads
  • External threads
people turning plastics

In which industries are plastic turned parts used?

Plastic turned parts are used in many industries where precise functional parts with specific properties are required. Typical applications include:
white insulating flunge
Mechanical and plant engineering
Hydrophone housing
Fluid technology
peek retaining ring
Semiconductor industry
peek dosing stamp
Medical technology
white stamp
Process engineering
blue single use cell
Biopharmaceutical industry

Mechanical and plant engineering

Beispiel: Insulating flange

Fluid technology

Beispiel: Hydrophone housing

Semiconductor industry

Beispiel: Retaining ring

Medical technology

Beispiel: Dosing stamp

Process engineering

Beispiel: Stamp

Biopharmaceutical industry

Beispiel: Single use cell

Which plastics are suitable for turning plastics?

At Ensinger, we machine a wide range of engineering plastics and have extensive experience in machining semi-finished products. Plastics such as PEEK, POM, PPSU, PSU, PPS, PA, or PTFE are particularly suitable for CNC turning. The customer typically selects the material, while we tailor our manufacturing processes to the specific material properties. We are happy to assist you with material consulting and help you select a suitable material for your specific application.
Material Consultation

Can turning and milling be combined when working with plastic?

On our CNC turning-milling centers, turning and milling operations can be combined into a single process. The following milling operations can be performed directly on the turned blank:
  • Cross holes
  • Milled surfaces
  • Fits
  • Contours
  • Grooves
Turning machined parts is often performed in a single setup. This improves accuracy, the positional relationships of the functional surfaces, and process stability. For long, slender components, the bar turning process can also be used. Automatic bar feeders and loading robots enable cost-effective mass production of CNC turned plastic parts.

FAQs

  • The achievable tolerances depend on the material, the part geometry, the stock shapes dimensions, and the machining strategy. Tight tolerance ranges are possible with dimensionally stable engineering plastics. However, the actual dimensional accuracy must always be assessed on a case-by-case basis.
  • Typical turned parts have an outer diameter of up to approximately 300 mm. For larger semi-finished products or solid components, a customized machining strategy is required.
  • Material-specific machining is crucial because engineering plastics behave differently than metals under temperature and mechanical stress. In particular, thermal expansion, lower thermal conductivity, and elastic material behavior affect dimensional accuracy and surface quality. An adapted machining strategy helps reduce deformation, limit dimensional changes, create stable functional surfaces, and ensure reproducible quality.
  • CNC turned parts are used wherever precise, rotationally symmetrical components with good sliding properties, chemical resistance, or electrical insulation are required.
    Typical plastic turned parts include:

    • Bushings and bearing components
    • Sealing rings and guide rings
    •  Valve components
    • Shafts and spacer sleeves
    • Threaded elements and connecting parts
    • Cylindrical housing and functional parts