Rethinking Machining:  In industrial machining, productivity is often discussed in terms of machine parameters, automation levels, and cutting tool technology. Less visible, but just as decisive is the material itself. Its metallurgical properties influence cutting speed, chip formation, tool life, and surface quality and therefore the stability of entire manufacturing processes.Especially in series production, it becomes clear: fluctuations in the material directly affect costs, throughput times, and process reliability. What may seem manageable in a single case can quickly become a risk factor at high volumes. 

Many machining shops know this challenge from everyday practice. When an order runs smoothly, the result is usually the interaction of many parameters. Conversely, even minor differences between batches can lead to unfavorable chip formation, increased tool wear, or critical tolerances. The consequences are machine downtime, rising scrap rates, and growing effort to keep processes under control.Against this backdrop, machining-optimized steels are gaining increasing attention. The goal is not only good machinability in individual cases, but reproducible results under series conditions—with minimal variation and high process robustness. Material solutions that address exactly this become a key lever for efficiency, resource conservation, and competitiveness.

Which metallurgical levers influence machinability? Which product families address which challenges? And how can productivity and process reliability be improved in measurable terms while considering environmental requirements and the responsible use of resources?

What sounds logical on paper is demanding in practice because these objectives can be in tension. The task is to achieve the right compromise between machinability and service properties, and to control it reliably throughout the manufacturing process. At its core, the machining industry pursues five objectives and all of them are directly linked to the material:

• Productivity: high cutting speeds, long tool life
• Dimensional accuracy: tight tolerances, excellent surface quality
• Process control: optimal chip breakage behavior, stable chip formation
• Reproducibility: consistent performance from batch to batch

• Environmental compatibility: avoiding environmentally relevant additives where possible, low-CO₂ processes, waste reduction

Swiss Steel Group controls the metallurgical processes end-to-end: from scrap input through melting and refining processes to steel processing. The result is high quality and consistent properties across all batches an essential factor for stable series production.

Transformation. Targeted modification creates something new. Modern materials science methods make it possible to adapt special steels to new requirements both in their performance properties (e.g., strength, toughness, corrosion resistance) and in machining properties such as machinability. How steel is optimized for machining.

Three areas play a central role:

• Chemical composition (alloying elements in defined quantities)
• Microstructure (e.g., ferritic-pearlitic, martensitic, austenitic)
• Non-metallic and oxide inclusions

Often, even a very small addition of individual alloying elements is enough to significantly change machining behavior. These targeted interventions enable improvements without fundamentally shifting the entire material system.

For machining-optimized designs, the following elements are particularly relevant:

Sulfur

Sulfur combines with manganese to form manganese sulfides. While these can be considered weak points in some applications, they are deliberately used in free-cutting steels to improve machinability. The amount and size distribution of sulfides determine how machining performance and service properties are balanced. Examples include Opticut+ and HSX® Z12.

Lead

Lead forms a second phase with a low melting point in steel. This has a lubricating effect and improves chip fracture behavior, without significantly impairing service properties. At the same time, environmental and safety-related constraints must be considered—therefore alternatives are becoming increasingly important.

Phosphorus

Phosphorus can support chip breaking and surface quality, especially in low-carbon free-cutting steels. As with all additions, dosage is decisive.

Calcium

Calcium “liquifies” hard, abrasive oxide phases. When used in a targeted way, oxides can have a lubricating rather than abrasive effect during machining. Corresponding special products are Opticut, SwissCut®, UGIMA®, and UGIMA®-X.

Boron

Boron is experiencing a renaissance as a means of improving machinability, including for partial substitution of lead. With defined processes, complex inclusions can form (borates and boron nitrides) that enable very good machining properties. One example is 11SMn30+BX.

Machinability is not a marketing claim - it has to be measurable. That is why Swiss Steel Group operates its own research center with machine tools and standardized test methods to evaluate, compare, and requalify machining performance over the long term.Key methods include, among others:

• Productivity measurement in industry-oriented turning tests: Typical improvements are often in the range of 10–20%, and in some cases up to 50%.
•  Chip formation and chip breakage analysis: For example using quick-stop tests to better understand mechanisms such as segmented chip formation.
• Standardized test series such as VB15 tests or chip breakage diagrams to ensure objective comparability.

• Zero-series tests with dummy components that simulate real industrial manufacturing processes (multiple operations, up to 1,000 parts without tool change).

In addition, a structured requalification process verifies that machinability remains consistent over many years a critical factor for series manufacturers and machining shops that depend on reproducible performance.

Four steps toward more stable machining. Increasing productivity does not always require changing the machine. In many cases, a structured approach combining material selection and parameter optimization is the fastest and most effective lever: 

Step 1: Clearly define the problemWhich operation? Which tool? Which cutting data? Which lubrication strategy? Which symptoms (chip shape, surface quality, tool life, dimensional accuracy)? 

Step 2: Select the right material conceptIs the primary focus on chip breakage, tool life, corrosion resistance, or avoiding heat treatment?This is where it becomes clear whether SwissCut®, Opticut(+), ETG®, HSX®, or UGIMA® / UGIMA®-X is the most suitable system. 

Step 3: Optimize parameters in a targeted wayBased on reliable data and recommendations, the optimal operating window can be defined – often delivering quick gains through adjustments to feed rate, cutting speed, tool geometry, or cooling and lubrication strategy. 

Step 4: Ensure reproducibilityA pilot run is a good start – but what truly matters is stability across batches. This requires defined material data, full traceability, and, where necessary, requalification.

In application, the focus is often on recurring, very tangible objectives: longer tool life, controllable chip formation, stable surfaces, and reliable results in series production. Swiss Steel Group addresses these needs with product families developed specifically for machining—particularly ETG®, HSX®, UGIMA®, and UGIMA®-X—with the aim of significantly increasing customers’ productivity (in many cases in the range of 10–20%, and in some cases higher).

For around 30 years, Swiss Steel Group has supported customers with application-oriented advice and technical expertise. In addition to material data and machining recommendations, this includes analyses as well as full traceability of manufacturing processes to identify and implement optimization potential.

Anyone who looks at machining only through the lens of the machine and the tool overlooks a key lever. Machining-optimized steels are designed to make machining processes more efficient, more stable, and more reproducible from batch to batch. The decisive factor is metallurgical process control across the entire manufacturing chain, combined with application-oriented technical support. Sustainability is an integral part of the approach. All Swiss Steel Group steels carry the “Green Steel” label because they are made from over 90% recycled raw materials and are melted in electric arc furnaces using 100% electricity from renewable energies. This links process performance with the ambition to use resources efficiently and reduce emissions.