Aluminium is one of the most frequently machined materials in modern industry. It combines low weight with good strength and is highly suitable for CNC milling and CNC turning. For this reason, it is widely used in aerospace, automotive, electronics, medical applications and special-purpose equipment.

To fully leverage the potential of aluminium, it is crucial to select the right alloy, appropriate machining technology and optimal cutting parameters. Below we present best practices used at RIMET when machining aluminium components for customers in Poland and across the European Union.

Why is aluminium so popular?

1. Material characteristics

Aluminium is characterised by:

• low weight,
• good thermal conductivity,
• natural corrosion resistance,
• ease of machining and anodizing.

These features make it ideal for producing lightweight, visually appealing components that can withstand demanding environmental conditions.

2. Applications across different sectors

Aluminium machining is commonly used in:

• aerospace,
• automotive,
• electronics (heatsinks, housings),
• medical devices,
• automation and robotics.

Choosing the right aluminium alloy

Different alloys behave differently during machining. The most commonly used include:

6061 / 6082 – universal structural alloys
Easy to machine, corrosion-resistant and highly suitable for anodizing.

7075 – high-strength alloy
Used in aerospace and precision mechanics. It requires stable fixturing and tightly controlled process conditions.

2024 – excellent fatigue strength
Ideal for dynamically loaded components, but typically requires protective coatings.

At RIMET, we always select the alloy based on the real-life application, taking into account strength, cost and machining requirements.

Best practices for machining aluminium

Optimised cutting parameters

Aluminium allows for very high cutting speeds but requires stable conditions. Key rules include:

• using high cutting speeds,
• selecting feed rate carefully (too low increases friction and heat),
• separating roughing and finishing operations,
• protecting thin walls against deformation.

Tools dedicated to aluminium

The best results are achieved with tools that have:

• sharp cutting geometry,
• polished flutes for effective chip evacuation,
• 1–3-flute end mills for high-speed machining,
• turning inserts with positive rake angles.

Depending on the application, both uncoated tools and coatings dedicated to aluminium can be used.

Effective cooling and lubrication

Machining aluminium generates significant heat, so coolant has a strong impact on surface quality:

• clean, properly maintained coolant is essential,
• the flow and direction of coolant must be appropriate,
• overheating of thin-walled components should be avoided.

How to avoid common problems in aluminium machining?

1. Preventing built-up edge and material adhesion

Aluminium can adhere to the cutting edge, resulting in poor surface finish and accelerated tool wear. To minimise this risk:

• use appropriate tool geometry,
• ensure effective chip evacuation,
• maintain sufficient coolant flow and pressure.

2. Deformation of thin-walled components

To reduce the risk of distortion, it is worth:

• reducing depth of cut,
• using multiple light finishing passes,
• planning the sequence of operations carefully,
• ensuring stable and rigid fixturing of the part.

The importance of surface finishing

Aluminium responds very well to various finishing processes, such as:

• anodizing,
• glass bead blasting,
• polishing,
• technical cleaning,
• laser marking.

These processes improve corrosion resistance, appearance and durability of the components.

Summary

The most important factors in aluminium machining are:

• selecting the right alloy,
• using proper tool geometry,
• stable cooling and chip evacuation,
• quality control at every stage,
• appropriate surface finishing.

RIMET provides a complete process: from CNC programming and machining, through measurement and quality documentation, all the way to final finishing of the parts. Thanks to this, our customers receive precise, repeatable components that are ready to use in the most demanding applications.