Current technology used by metal spinners
Metal forming, as used by metal spinners, has become an important manufacturing process, mainly due to the superior metal yield/properties of the finished spun metal. Traditional cold forming metal shaping techniques are becoming out dated - tooling is by the most part cumbersome and has to meet high standards in terms of accuracy and longevity and so for metal spinners, on an economical level only really lends itself to high volume metal spinnings. In contrast, metal chip forming has the advantage of high output and quality, but is limited in the shapes it can produce.
Metal spinning and metal flow forming are exceptions to the above. Metal spinning and metal flow forming can be used to produce spun metal hollow parts which differ greatly in shape and variable wall thickness, without compromise to the general benefits of metal forming. Changes in shape can be produced in almost any part of the spun metal. Other production methods can also be employed in the same cycle. Largely, tooling is not dictated by component shape of the spun metal. These features make metal spinning an economical and highly flexible process, suitable not just for medium and large-scale production but also for small volume and one off's.
All cold working metals can essentially be spun metal or flow formed metal. Hot working can be used in special circumstances. As with most metal cold forming processes, spun metal or flow-formed metal parts show a fully worked, compacted grain structure as well as a characteristic surface finish. Moreover, the stress component generated in the part by the spinning tools produce exceptionally high work rates – in certain circumstances wall thickness is reduced by 90% by metal flow forming. Work rates of this magnitude introduce a high level of cold work hardening on the spun metal which, together with the properties mentioned above, lead to good fatigue strength and reduced notch sensitivity. Wall thickness can therefore be reduced or low-cost materials used which still in fact meet the mechanical strength required for the finished spinning.
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