CNC knowledge - Radmot

Best practices in aluminium machining to ensure precision and durability of parts

Written by Radmot | Mar 24, 2026 10:45:02 AM

Aluminium is one of the most widely used materials in industry. Its lightness, corrosion resistance and excellent conductivity make it indispensable in projects requiring strength and precision. However, achieving high dimensional accuracy and optimum strength in aluminium parts requires the use of appropriate machining practices. Below, we outline the most important of these – from tool selection and cutting parameters to cooling strategies and stress control.

Key cutting parameters for aluminium

Cutting parameters determine, amongst other things, the efficiency of the process, the durability of the finished components, surface quality and the final geometry of the workpiece – particularly in mass production, where the margin for error must be minimal. Properly selected CNC aluminium machining not only increases efficiency but also ensures dimensional consistency across every batch.

The selection of aluminium machining parameters is crucial for achieving optimal machining results. Factors such as the following must be taken into account:

  • cutting speed – aluminium allows for significantly higher speeds than steel or titanium alloys; typically 300–1500 m/min,
  • feed rate – higher than for steel, which reduces machining time,
  • cutting depth – dependent on the workpiece design and the rigidity of the clamping.

Incorrect setting of these parameters leads to the formation of burrs, overheating, and even deformation of the workpiece. RADMOT, utilising over 80 state-of-the-art CNC machining centres, selects cutting parameters individually for each order, taking into account the properties of the specific alloy and the final application of the component. This approach not only optimises production time and cost, but above all guarantees high dimensional repeatability, which is crucial in sectors such as the automotive and medical industries.

Selection of cutting tools

For materials such as aluminium, selecting the appropriate tools for aluminium is essential for effective and efficient machining. The following tools are recommended:

  • high-sharpness solid carbide (VHM) cutting edges,
  • diamond or TiAlN coating (for more abrasive alloys),
  • geometry enabling effective chip evacuation.

As noted by a RADMOT technologist – to achieve a perfect surface finish when milling aluminium, tools with a large rake angle and polished chip flutes are used. This significantly improves the quality of the finish and eliminates the need for additional machining.

The correct choice of tools minimises the risk of deformation and ensures greater tool life, which translates into lower unit costs in high-volume production. Furthermore, it directly affects the strength of the aluminium, particularly in areas subject to mechanical stress or prone to microcracks.

Cooling strategies during machining

Cooling during the machining of aluminium serves two main functions: it prevents the material from overheating and aids effective chip removal. Among the proven cooling methods, the following are worth mentioning:

  • non-emulsifying oil cooling,
  • conventional liquid cooling (water-oil emulsion),
  • compressed air cooling (for dry machining).

The choice of method depends on the type of operation – dry milling of aluminium allows for a higher surface quality, but requires perfectly matched tools and parameters. In contrast, for aluminium turning in mass production, liquid cooling ensures greater process stability. Precision CNC turning – see what we offer at RADMOT.

Control of material stresses during machining

High dimensional accuracy and long-term strength of aluminium depend not only on the cutting process, but also on the ability to control internal stresses. Stress control helps to prevent deformation after the workpiece is removed from the fixture or during its service life. In practice, the following methods are used, amongst others:

  • gradual removal of material from both sides (symmetrical machining),
  • programming operations taking into account the stress distribution in the semi-finished product,
  • the use of stress-relief heat treatments (T6, T651),
  • planning appropriate breaks between cutting stages.

At RADMOT, we implement strategies to minimise the effects of stress – particularly important in the production of precision components for the automotive, medical and electronics industries. Thanks to our experience and the use of specialist analyses, we are able to identify potential critical points as early as the prototyping stage.

Aluminium finishing – how to achieve a perfect surface

To achieve a perfect surface on an aluminium component, appropriate finishing machining of aluminium alloys is essential. This comprises:

As RADMOT’s experience shows, the choice of final finishing technology depends on the target industry. For the consumer products sector, appearance is often key, whereas electrical engineering prioritises durability and the repeatability of geometric parameters.

With our own anodising facility, we offer a comprehensive approach to the entire aluminium finishing process. Anodised parts at RADMOT meet ISO standards and are used in both mechanical and electronic systems.

Discover our modern RADMOT CNC machine park

At RADMOT, we carry out complex projects involving the machining of aluminium alloys, offering full support – from the consultancy stage, through prototyping, to large-scale production. Our machine park comprises over 80 machining centres, CNC lathes, specialist measuring equipment and an anodising line. We offer:

We serve a range of industries, including: machine building and automation, electrical engineering, automotive, and the medical industry.

If you are looking for a partner to produce precise, durable and aesthetically pleasing aluminium components – please contact us. The RADMOT team will help you select the optimal technology, carry out your project from start to finish and take full responsibility for quality. Discover our modern CNC machine park and request a free quote.