The invention is an improved wire straightener die for rotary wire straightener machines and devices used in the production of wire and wire related products from various metals. Each wire straightener die consists of a single unit which is normally used with four other similar dies in a sequence arrangement. The die of this invention is used in any standard rotating wire straightening arbor. Each die in the sequence contains a hardened center core which increases the life of the die. Each die can be installed in the arbor in any one of four different positions, thus giving complete flexibility of use of the die.