There are clear differences in size accuracy, surface quality and strength levels between cold-drawn and hot-rolled K500 bars. Cold-drawn bars are formed by drawing through molds, with tighter diameter tolerances (controlled within h9–h11 grades), higher surface finish, and the processing hardening introduced during cold processing can further enhance strength before aging. Hot-rolled bars have relatively looser size tolerances and surface oxide scales, and need to be machined or ground before being used for precision parts, but have lower production costs and are suitable for large-diameter specifications (usually greater than 50mm). In terms of mechanical properties, both can meet the standard requirements after aging treatment, but due to the contribution of processing hardening, the yield strength of cold-drawn bars may be slightly higher than that of the same specification hot-rolled bars. Material selection suggestions: For small-diameter precision parts (such as fasteners, valve stems), cold-drawn bright bars are preferred; for large-diameter structural components (such as valve bodies, pump shell blanks), hot-rolled black-scaled bars can be selected to control costs.
Jiangsu Cunrui Metal Products Co., Ltd. We can supply cold-drawn and hot-rolled K500 bars, with specifications ranging from 6mm to over 250mm. For specific dimensions and surface requirements, please contact us to confirm the inventory.