Reliable development partner for sophisticated materials in battery-powered garden tools

Battery-powered garden tools are becoming increasingly popular with gardening and landscaping companies as well as amateur gardeners. Compared to established models with combustion engines, however, the components of many of these garden tools have to meet new requirements. Take a chainsaw, for example: the instantaneous torque provided by the electric drive system requires new material solutions for the chain links. This is precisely where Waelzholz comes in with its technical expertise and many years of experience, which makes us a reliable development partner.

“Batteries for garden tools are becoming increasingly powerful. And not just in terms of their storage capacity, but also in terms of their power output,” explains Thorsten Köhler, who heads up the Materials Technology Department at Waelzholz in Hagen. “That’s why we’re seeing increasing demand for battery-powered gardening tools, especially in the professional segment. For us as a manufacturer of steel materials for relevant components such as chain links or blades, this means rethinking our processes and the materials used. This is because – unlike conventional models with combustion engines – electric motors deliver power differently. In this case, the full torque is available as soon as the device is switched on. Components such as the chain links on a chainsaw must be designed with this in mind.”

Let’s stick with the chainsaw example. If it is equipped with an electric motor, the entire torque load is abruptly transferred to the chain, causing a high, sudden load. As far as the chain and its individual links are concerned, this means that the material must exhibit significantly higher ductility, in other words, greater toughness. Engineer Köhler offers an explanation: “Abrupt tensile loads can plastically deform the chain material, which can lead to premature failure of the chain. A tough material that is adapted to the load prevents this.”

The challenge in material development in this case is that the required high degree of ductility represents an extension of the range of properties, because the material used here must continue to retain its hardness, resistance to wear, heat resistance, and other specifications. As Köhler explains: “A targeted approach to material development is required in this case, because every change in individual parameters has an influence on other material factors. This is precisely where one of Waelzholz’s greatest strengths lies: working together with our customers to develop customized solutions that perfectly meet their requirements.” And we don’t just face these material challenges when it comes to our cold rolled steel strip for sawing applications. We similarly need to find new solutions for the steel materials used in hedge trimmers when they are converted to battery-powered operation.

Joint material development projects with customers offer a great deal of potential, explains the materials expert: “Often, the focus isn’t only on achieving the perfect properties for the final product, but also about excellent further processing, for example in forming or punching processes. In this context, it isn’t enough to just look at our own processes; rather, we need to keep the entire value chain in mind.” This also applies to the raw material side, as Köhler explains: “In order to precisely meet the requirements of the finished product, our development work begins with the hot-rolled steel strip. Together with our suppliers, we carefully coordinate the metallurgical composition of the raw material and often develop completely new solutions.” All this with the aim of being a reliable development partner that offers material solutions to our customers which give them a real competitive edge.