Stainless steel is an essential material across numerous industrial sectors: from automotive to home appliances, from hydraulics to medical. Its mechanical properties, corrosion resistance, and durability make it ideal for high-performance applications. At the same time, however, these same characteristics turn stainless steel turning into a complex technical challenge. Achieving high-quality results requires specific expertise, advanced lathes, and an in-depth knowledge of the different types of this alloy.
The intrinsic complexity of stainless steel turning
Compared to carbon steels, stainless steel stands out for its corrosion and high-temperature resistance, but it also brings greater machining difficulties.
Work hardening is likely the most critical factor to manage during stainless steel turning. This phenomenon causes rapid surface hardening of the material near the cutting zone, creating increasingly harsh machining conditions that can compromise both part quality and tool life.
The high toughness of stainless steel means greater resistance to plastic deformation, requiring higher cutting forces than traditional steels and generating greater mechanical stress on the machine–tool system. The formation of long and complex chips further complicates the automatic stainless steel turning process.
The chromium content in alloys above 10.5% also leads to the formation of a passive oxide layer, significantly affecting the material’s behavior during cutting.
Automatic stainless steel turning of austenitic steels
Austenitic steels, such as the 300 series alloys, are among the most commonly used due to their excellent corrosion resistance. However, their high ductility results in strong tendency to galling and burr formation during machining, making it difficult to maintain tight tolerances and consistent surface finishes. In addition, strain hardening can shorten tool life. During the automatic stainless steel turning process, areas affected by plastic deformation experience a rapid increase in hardness—up to 150% higher than initial values. This behavior requires machining strategies that minimize deformation zones and maintain stable cutting conditions to prevent localized work hardening.
Machining austenitic steels demands high-performance tools with geometries specifically designed to handle elevated cutting forces and long, tough chip formation.
Cutting parameters for stainless steel turning with austenitic alloys must be carefully calibrated to balance productivity and quality. Moderate cutting speeds help control temperatures in the cutting zone, while relatively high feed rates promote chip stability and reduce tool-workpiece contact time, limiting heat buildup.
Stainless steel turning of martensitic grades
Martensitic steels represent a particular category of stainless steels, characterized by high hardness and mechanical strength, achieved through heat treatments that generate a martensitic crystalline structure. These features place extreme stress on machines. Their lower ductility compared to austenitic steels results in a different chip formation mode—generally more brittle but capable of causing significant abrasive tool wear.
To handle these alloys, it is crucial to use lathes with high structural rigidity and to choose cutting tools with careful consideration of edge material properties. Lower cutting speeds help control tool wear and maintain dimensional stability during automatic stainless steel turning. Reduced feed rates lower cutting forces and improve surface finish.
Stainless steel turning of duplex alloys
Duplex stainless steels combine the corrosion resistance of austenitic grades with the mechanical strength of martensitic ones. However, this dual nature makes machining particularly challenging: high cutting edge stress and low thermal conductivity demand precise control of process parameters. The cutting parameters for duplex stainless steel turning must be carefully balanced to accommodate the material’s mixed structure. The high mechanical strength—often twice that of austenitic steels—requires significant cutting forces, which must be managed by selecting appropriate tools and optimizing process conditions.
Moderate cutting speeds ensure stable cutting conditions. Well-calibrated feed rates offer the best compromise between productivity and part quality.
Sarbo’s technologies and equipment for stainless steel turning
Successfully managing the complexity of stainless steel means turning a demanding material into a high-performance component. This is only possible through an integrated approach combining know-how, advanced technologies, and certified production processes.
Sarbo operates modern stainless steel turning centers, equipped with sophisticated control systems for real-time management of process parameters. The integration of cutting force monitoring systems enables immediate detection of abnormal conditions that could affect part quality or accelerate tool wear.
At Sarbo, performance is monitored through the OEE system (Overall Equipment Effectiveness), and stainless steel turning processes are developed using Lean Production and Six Sigma methodologies to minimize waste and optimize production costs.
Back to top