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Cold forming has revolutionised many metal manufacturing processes but, historically, its ability to process stainless steel has been more limited. The exceptional hardness of stainless steel puts heavy demands on tooling and machines, unlike the relatively soft and malleable metals (copper, brass and alloys) that have already been conquered by cold forming.
Now, thanks to innovative development at Dawson Shanahan, we are able to cold form stainless steel billets, to high levels of precision and in volume. We can now even cold-form other exotic metals such as titanium.
The cold forming process significantly improves the mechanical properties of the finished component, with a finished part 18 percent stronger than that of machined parts. Unlike machining where sections are usually cut across the grain structure of the metal, the direction of forming and the geometry of the part is aligned with that of the grain. In addition, finished parts can have complex internal and external geometries, with exceptionally smooth surface finish. This offers the potential for design engineers to produce components of a higher specification and provide that competitive edge in performance.
The capability to cold form steel offers tremendous opportunities to manufacturers of ultra-high precision parts, including laser applications, where cold formed nozzles significantly increase cutting accuracy, or diesel injectors, which are generally more reliable than conventionally manufactured parts when used with biofuels.
Dawson Shanahan’s new method of cold forming uses specialised material lubrication and protection coatings, applied to each billet prior to forming, plus enhancements in the handling and extrusion process. Combined, these refinements allow high precision stainless steel parts to be produced in small or large volumes, while retaining all of the traditional benefits associated with conventional cold forming, such as almost zero scrap.
There are still times when machining is necessary and a degree of machining can sometimes be used to finish a primarily cold-formed part. However, as economic and environmental pressures drive manufacturers to find new ways to reduce material waste and energy consumption, cold forming looks set to supplant machining as the method of choice in many applications.
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