The article presents a comparison of three trochoidal paths: written by G-Code, generated using overlays from the machine level, and generated using the CAD/CAM environment. The parameters determining the effectiveness of the process were: maximum achievable feed rate, surface roughness and waviness, cutting forces and cutting temperature when milling NC6 steel (50HRC) using a 10 mm cutter diameter. The main measurement results include: increase in the maximum feed rate value by almost 35% when using paths A and C compared to path type B and nearly a double increase in surface roughness when using path generated using CAD/CAM environment compared to B path. The most important conclusions – it is not always possible to machine with the recommended parameters by the tool manufacturer, especially when machining narrow grooves. It has been proved that the use of paths with the displacement described by arcs and straight lines as a trochoidal step over reduces the possibility of milling at high feed rate.