Mechanical turning is one of the most important processes in the industry, as it allows the manufacture of components with a high degree of precision. The rotary movement typical of this process enables the machining of various types of metal, with a chip removal process that produces mechanical components of diverse shapes, designs, and sizes, essential in numerous sectors.

From traditional supply systems, the industry has now shifted to digitised and automated systems, supported by cutting-edge CNC equipment that allows millimetre-precision. CP Group has gained solid expertise in the field of turning and can ensure quality machining thanks to the internal staff’s know-how and a network of external partnerships with proven experience over years of collaboration.

Metal turning with CP Group

The quality of our machining services begins with meticulous design, analysing the most efficient solutions and identifying operations and materials most suitable for manufacturing mechanical components. Double quality control ensures that the conformity of each product (to international standards and customer requirements) is checked first at the partner facilities where production takes place and then in our internal metrology room.

The availability of machinery managed by CNC software allows us to design and build pieces with diverse and complex designs, fully meeting the client’s requirements. Adhering to rapid timelines and flexible methods, we can handle oversized pieces as well: our creations include components with a diameter of over two meters.

Roughing and finishing operations, typical of turning processes, make it possible to obtain pieces with particular shapes, such as contoured or tapered, and featuring special holes or grooves. CP Group can manage any turning operation to produce outputs like shafts, pins, or threaded bars, essential in various sectors such as


Aluminium turning, stainless steel turning and other materials

During the design phase, analysis of the indications, technical drawings, or prototypes provided by the client allows CP Group’s technicians to consider the best raw material to use in subsequent turning processes.

ISO standards define six different groups of materials workable through turning, distinguished by chemical composition, hardness, malleability, and other decisive variables:

  • ISO group M comprises stainless steels containing at least 12% chromium, which can generate heat and wear on machining tools;
  • ISO group P consists of alloyed or heavily alloyed steels, varying in hardness but with excellent workability;
  • ISO group K is made up of cast irons, ranging from easy-to-machine grey iron to more complex nodular or compacted graphite iron;
  • ISO group N includes non-ferrous metals such as brass, aluminium, and copper – softer and less abrasive to machining tools, suitable for high-speed applications;
  • ISO group S comprises heat-resistant superalloys, including iron, titanium, nickel, and cobalt-based materials, which present some difficulties in machining compared to other raw materials;
  • finally, ISO group H includes steels with hardness HRc between 45 and 65 (including shell-moulded cast irons) and which are particularly challenging to machine due to abrasiveness and high heat generation.


Internal turning and external turning: the differences

There are numerous variables in turning processes, such as the type of tools (lathes) used, rotational speed, or the type of output desired. One of the most important classifications of turning operations is between external and internal turning: what sets them apart?

In essence, it is to do with whether chip removal occurs externally or internally to the workpiece, but the differences are numerous, and each system entails different specific types of processing.

Operations that can be carried out externally to the workpiece include:

  • the actual turning, i.e. the removal of material to give a shape (often conical or cylindrical) to the piece;
  • facing, for obtaining smooth surfaces;
  • threading, which gives a helical shape to the workpiece, making it compatible with another;
  • grooving, to obtain grooves on the finished component;
  • shearing off, performed when the goal is to separate a section of the component.


The main internal turning operations include:

  • drilling, for creating holes in the machined component;
  • boring, a machining operation that corrects the axiality and diameter of previously obtained holes;
  • tapping, or the creation of a thread inside the piece.


Our know-how for mechanical turning

CP Group is able to design and supply customers with both standard and customised turned components. Our specialisation lies in producing custom mechanical components based on the client’s specific needs.

One of the significant advantages we are proud to offer to the market is the consolidated and continuously updated expertise of our internal collaborators, capable of engineering projects and executing reverse engineering processes using advanced instruments and software. All of this is done with the utmost protection of the confidentiality and privacy of each order, which is internally coded and stored in secure virtual databases.

In our commitment to becoming a complete service provider, we also offer reliable storage and shipping systems, as well as complete management of each customer’s supply chain. The high level of technology in our warehouses, combined with rapid or just-in-time shipping, aims to position CP Group as a perfect partner for lean production and the application of Kanban methods to production.

Cost optimisation, warehouse outsourcing, customised supplies, and loyalty programs are all geared towards making our brand an international reference point for anyone needing to design and produce high-standard components through mechanical turning processes and CNC metal machining.

Contact us to start working with us now!