Hard part turning offers manufacturers the opportunity to replace expensive grinding processes, reduce cycle times, and improve machining productivity. However, as with many advanced machining techniques, success depends on overcoming a number of specific challenges. Ralph Löwenau, Product Solution Specialist for Turning at Sandvik Coromant, an expert in metalcutting and production solutions, explores the obstacles manufacturers face in hard part turning and how these can be transformed into opportunities for greater efficiency and profitability.
Hard turning generally refers to the machining of parts with a hardness greater than 45 on the Rockwell hardness scale (HRC). For context, mild steel has a hardness between 10 and 20 HRC, while hardened steel parts used in the automotive and aerospace industries can have a hardness between 45 and 70 HRC.
Turning hard parts is made possible by super-hard cutting tool materials such as cubic boron nitride (CBN) and advanced ceramics. These materials are second only to diamond in hardness, meaning they can withstand the extreme forces and temperatures generated when cutting materials such as hardened steel.
Unlike conventional carbide inserts, which would wear almost instantly under these conditions, CBN grades maintain cutting edge strength and resist both abrasive wear and thermal shock. Additionally, the inserts are designed with special cutting edge preparations and coatings that help manage heat, reduce chipping, and ensure consistent tool life. However, even with the best tools available, turning hard parts still presents challenges.
Exploring common challenges
The extreme hardness of the workpieces can accelerate insert wear, and if tools are not carefully selected or process parameters are not optimized, chipping and edge breakage can occur. Achieving the required surface finish and dimensional tolerances places additional demands on machine setup, toolholder stability, and cutting data.
Hard part turning can be an excellent substitute for grinding, as it can provide comparable quality while reducing cycle times. However, many operators consider grinding the benchmark for surface finish, and achieving comparable quality is important when choosing an alternative method.
High hardness leads to increased cutting forces and significant heat in the cutting zone. This can push the insert temperature above 1000°C, with the risk of thermal cracking, accelerated crater wear, or even workpiece deformation. Without the right insert material and optimized cutting conditions, this additional heat can degrade tool performance and compromise dimensional stability.
Seize the opportunities
To overcome these challenges and succeed in hard part turning, manufacturers should consider tool selection and process planning as strategic investments. CBN grades are the best choice for hard part turning, with many modern grades featuring optimized edge preparations that offer both wear resistance and edge security, allowing for greater stability and increased productivity.
There are two typical preparations for CBN inserts: S-type and T-type. S-type inserts have the best edge line strength and are resistant to microchipping for a more consistent surface quality. T-types are ideal for surface finishes with continuous cuts and minimize burr formation in interrupted cuts.
To further improve part quality, process optimization is equally crucial. Manufacturers should consider their hard turning strategy from the outset, even before the materials are actually hardened. When soft turning, before heat treatment, adding small angled edges to remove sharp edges (known as chamfering) and machining rounded transitions instead of sharp edges (also known as radiusing) can help prevent imperfections that could be transferred to the hardening process, where they would then be more difficult to remove.
When turning hard parts, it's recommended not to jerk the tool out of the cut when entering or exiting. Instead, smooth entry and exit helps prevent stress buildup and edge damage, which can compromise both tool life and component quality.
Hard part turning is a valuable machining strategy when manufacturers seek to improve production efficiency and streamline their processes. However, it is not without its complexities. Choosing the right inserts, machine stability, and careful process planning are all critical to successful turning. Following expert guidance and leveraging advanced tooling solutions can help manufacturers achieve grinding-quality results with shorter cycle times and lower costs.
Still: update of the exv 14-20 and exp 14-20 forklifts and the exh 14 and exh-s 20-25 pallet trucks
STILL, a leading supplier of intralogistics systems and equipment, continues to expand its portfolio to maximize customer benefits by updating four models, in line with its commitment to developing perfectly adapted and highly efficient warehouse equipment for every application. Optimized functions, technologies, and safety features, combined with the latest innovations, further improve the trucks' suitability, safety, and efficiency. This allows warehouses to be organized even more efficiently in terms of space, time, and costs, helping companies meet the demanding and dynamic requirements of intelligent warehouse organization. With the upgrade of the EXV 14-20 and EXP 14-20 stackers and the EXH 14 and EXH-S 20-25 pallet trucks , STILL continues to optimize and expand its portfolio of warehouse technology. The newly launched trucks will make it even easier for companies to find the most suitable, efficient, sustainable and cost-effective solution for each application. “The sector is characterized by great dynamism. Requirements and applications often change rapidly and radically, requiring a high degree of flexibility and adaptability from companies,” explains Marco Fornara, Head of Sales & Marketing Support at STILL Italia. “For us, as a manufacturer, this means continuously developing and optimizing our solutions and trucks so that we can always offer customers the best and most personalized solution to their needs. In addition to hardware adaptations, rapidly evolving technologies also play a key role in this process.” Last year, STILL expanded its range of warehouse trucks by updating the EXV 10C–16C and EXD 18C–20C stackers and the EXH-L 16–20 pallet truck, laying the foundation for its customer-oriented portfolio dedicated to intelligent warehouse organisation. Horizontal transport and loading/unloading of trucks made easy: the STILL EXH-S 20-25 and EXH 14 pallet trucks Hot on the heels of the launch of the AXL iGo, the first automated solution for loading and unloading trucks, STILL is also introducing the EXH-S 20-25 and EXH 14 electric pallet trucks, featuring new functions and innovative improvements. The latest version of the EXH-S 20-25 pallet truck with fixed platform has a load capacity of up to 2,500 kg and a top speed of 14 km/h. It provides reliable support for demanding tasks and long transport distances. The innovative STILL tiller with integrated display responds to customers' preference for controlling the truck using the familiar tiller. The SafetyLight integrated into the chassis, the optional platform suspension in the Plus version, and the intelligent foot sensor also ensure greater safety and comfort. The latter can be configured to move only when the operator's feet are within the truck's contours, or to only allow low-speed mode when a foot is detected by the sensor. To ensure optimal utilization of the truck throughout its entire life cycle, the EXH-S 20-25 can be easily integrated into the STILL Smart Portal fleet management system. For lighter applications and short distances, the new EXH 14 pedestrian pallet truck is the ideal choice. This extremely maneuverable truck effortlessly moves loads up to 1,400 kg in horizontal transport and can be easily operated even in the tightest spaces, even with the tiller fully extended. Its compact dimensions also make it a particularly flexible warehouse assistant: not only can it maneuver precisely inside a truck, but it can also be transported in the cargo area. Quick and safe storage, even in confined spaces: the STILL EXV 14-20 and EXP 14-20 forklifts The newly improved EXV 14-20 and EXP 14-20 pedestrian stackers make loading and unloading in narrow aisles and high racks more flexible and efficient, ensuring ergonomics and safety even over long distances. Both models are equipped with a powerful, low-maintenance engine and offer a load capacity of up to 2,000 kg. The extra-long, ergonomic, and responsive STILL tiller with OptiSpeed takes safety to a new level: it always maintains a safe distance between the operator's feet and the truck and automatically adjusts speed based on the tiller's inclination. Combined with the Curve Speed Control assistance system, the tiller ensures an optimal balance between maximum travel speed and safety when cornering, in narrow aisles, and during starting and braking. The EXV 14-20 is designed for particularly agile maneuvering in confined spaces, with stacking heights of up to 6 meters, while the EXP 14-20 is the ideal choice for maximum flexibility. Adjustable cantilever forks allow for easy handling of a wide variety of load units, as well as the convenient use of additional attachments via optional hydraulic functions. All forklifts can also be supplied with lithium-ion batteries, which ensure high operational availability and flexible charging, even while working. Customers thus receive a forklift perfectly tailored to their needs and requirements, while also benefiting from a cutting-edge energy system that effectively combines availability, efficiency, and sustainability.
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