DIN C45E steel is a medium carbon steel. It also is a general engineering structural steel. It have good machinability and high tensile properties. C45E steel normal supply steel Plate, Round bar, Flat bar, Square bar, Hexagonal bar, Pipe. Normal provide the hot rolled black surface, cold drawn birght surface, large size forging is better. Delivery harndess 18-25HRc. Refer the attachment for details:

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An investigation of the fatigue of CK45 steel in the as‐received state and after pre‐fatigue deformation

By: M. Shariati and H. Mehrabi

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