There is a growing need for geometrically complex components produced by CNC machining. Such components have vast applications in the automotive sector, aerospace industry, power generation (turbines), hydraulic devices, mold-die industries, and customized medical implants. Ballnose mill tools are conventionally used for five-axis milling of such components (e.g. bladed disks so-called blisks). These tools provide fine surface finish and flexibility in toolpath generation. However, the tool radius limits the radius of the cutting envelope. The maximum applicable tool radius is also restricted by the geometry of the component (e.g. in blisks). In addition, fine surface finish demands limited scallop height, which is obtained by adopting small values of stepover. Such constraints lead to longer processing time, whereas the competitive market calls for higher productivity. To address the problem, innovative circle-segment tools offer a significantly larger radius of the cutting envelope (engagement radius) per tool radiuses. Therefore, a significantly lower cycle time is feasible, whereas a good surface finish is preserved. The literature is scarce on robust and comprehensive simulation approaches for the modeling of the cutting forces and the prediction of dynamic stability in the five-axis milling process by using circle-segment tools. In the literature, some gaps are evident in terms of the edge (ploughing) effects, flank/slot/tip cutting scenarios, cutting coefficient calibration approaches, and the range of the process parameters studied. In the limited number of available studies, the dynamic stability criterion is either undisclosed or is merely founded on experimental outcomes without providing any analytical framework for prediction. Therefore, this study aims at developing a simulation approach for the prediction of the cutting forces and dynamic stability in five-axis milling by using circle-segment tools. The cutting-edges radius of the oval circle-segment tool was measured by employing light optical microscopy (LOM). To derive the dynamic properties of the tool and its Frequency Response Function (FRF), impact hammer tests were carried out on the tool. Three-dimensional digital twins of the cutting-edges profiles were generated in MATLAB based on one-dimensional measurements by laser and Linear Variable Differential Transformer (LVDT) sensors. An efficient tool-workpiece engagement model was developed to predict the uncut chip thickness and chip area. The cutting coefficients (shear and edge coefficients)were calibrated by adopting two methods. For this purpose, and to validate the force predictions, a series of five-axis cutting tests were performed at variable feeds (25 to 65), constant spindle speed (3500 rpm), and tilt angle (84.08º). The workpiece was additively manufactured titanium alloy blocks. To experimentally investigate the dynamic stability and chatter, several five-axis cutting tests were conducted at variable spindle speeds (3000 to 4000 rpm), depth of cuts (100 to 900 µm), and tilt angles (84.08º and 80º) along with a constant feed (55 µm). This experimental campaign involved the measurement of cutting forces, the three-axis acceleration of the workpiece, and cutting sound. The topography of cut surfaces corresponding to specific cutting conditions was investigated by employing a White Lite Interferometer (WLI). The stability map was predicted based on the calculation of dynamic chip thickness, force, and characteristic equation. For this purpose, the Nyquist stability criterion was adopted to conclude on the dynamic stability per cutting conditions, namely spindle speed and depth of cut. The Root Mean Square (RMS) of the recorded cutting force, workpiece acceleration, and surface roughness data were used to experimentally validate the predictions. The predictions of the cutting forces and stability map were acceptably validated by experimental data. The positive effect of the differential pitch, as identified in the tool, on dynamic stability was highlighted by the simulations. In addition, the effect of the ratio of the cutting edge radius to feed per tooth per revolution on the cutting coefficients and cutting mechanism was highlighted.