18th International Conference on Mobile Web and Intelligent Information Systems, MobiWIS 2022 -- 22 August 2022 through 24 August 2022 -- -- 281999, Tool wear prediction/monitoring of CNCs is crucial for improving manufacturing efficiency, guaranteeing product quality, and minimizing tool costs. As a computer-aided application, it has a significant role in the future and development of Industry 4.0. Sensors are the key piece of hardware used by data-driven enterprises to predict/monitor tool wear. The purpose of this study is to inform about the predominant types of sensors used for tool wear monitoring/prediction. This study serves as a resource for researchers and manufacturers by providing the recent trends in sensors for tool wear monitoring. Thus, it may help reduce the time spent on sensor selection. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.