The increase in strength of bars caused by drawing is associated to the average deformation (ε) imparted to the material by processing. This paper discusses the hardness profile method for evaluating the redundant deformation factor φ, which in turn allows the calculation of ε. For one drawing pass the results obtained are compatible with those from other theories, but it seems that a previous experimental hardness profile evaluation of ε in the literature involved improper calculations. For two successive passes a generalized definition of φ is forwarded. These passes work harden the material less than expected by the external deformation in the bar, and no current theories for φ calculation are adequate for more than one drawing pass.

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