Prediction of chip-breaking in machining is an important task for automated manufacturing. There are chip-breaking limits in maching chip-breaking processes, which determine the chip-breaking range. This paper presents a study of chip-breaking limits with grooved cutting tools, and a web-based machining chip-breaking prediction system. Based on the chip-breaking curve, the critical feed rate is modeled through an analysis of up-curl chip formation, and the critical depth of cut is formulated through a discussion of side-curl dominant chip-formation processes. Factors affecting chip-breaking limits are also discussed. In order to predict chip-breaking limits, semi-empirical models are established. Although the coefficients that occur in the model are estimated through machining tests, the models are applicable to a broad range of machining conditions. The model parameters include machining conditions, tool geometry, and workpiece material properties. A new web-based machining chip-breaking prediction system is introduced with examples of industrial applications.