In the paper, design and implementation of a method for increase of shearing blades life are described. Blades for shearing of a reinforcing grip bar are made of tool steel 55WCrV8 (19 733 according to Czech Standard). Plasma nitriding method, which allows higher surface hardness while maintaining a ductile core, was chosen as an optimal method increasing blades life. A scratch pattern and a hardness measurement of initial and modified samples confirmed improvement in blade surface hardness to a value of 64 HRC.