This study presents an analysis of degradation mechanisms of a forging die used in the hot forging process of a counterweight forgings. The investigated tool was made of hot-work X37CrMoV5-1 (1.2343) tool steel. The study was aimed at identification of the dominant degradation mechanisms of a hot forging die insert made of 1.2343 steel used in industrial conditions and correlation of those mechanisms with the microstructure, hardness distribution and operational thermal loading. The research methodology included macroscopic and microscopic examination of the die working surface, microstructural analysis using optical microscopy and scanning electron microscopy (SEM), fracture surface investigations, hardness measurements across the tool cross-section, numerical analysis of the die forging process, and dimensional assessment using 3D scanning. The results showed that the dominant degradation mechanisms were connected with thermal fatigue, abrasive wear, adhesive wear, and crack propagation in the subsurface layer of the die. Microstructural observations revealed a tempered martensitic structure as well as local microstructural banding promoting stress concentration and crack initiation. SEM analysis confirmed the brittle character of cracking with the presence of intergranular fracture zones. Hardness measurements indicated a non-uniform hardness distribution within the tool and an increased hardness of the surface layer exceeding 57 HRC. The obtained results indicate that the degradation of the forging die resulted from the combined effects of high temperature, mechanical loads, and intensive friction occurring during tool operation. The identified degradation mechanisms provide important information for improving the durability and operational reliability of forging tools used in hot forging processes.