Define ‘step over’ in CNC milling.

In CNC milling, ‘step over’ refers specifically to the tool's movement between successive passes. It is an important parameter that determines how the cutting tool overlaps on each successive pass as it progresses across the workpiece. A smaller step over results in finer, more detailed cuts, which can lead to a smoother surface finish, while a larger step over may remove material more quickly but might result in a rougher finish or less accuracy. This parameter is crucial when programming the milling operation to achieve desired results in terms of tolerances and surface quality.

Other definitions, such as the amount of material removed in one pass, focus instead on depth of cut rather than the horizontal movement of the tool. The speed of the spindle rotation pertains to how quickly the tool spins, affecting cutting efficiency but not directly related to step over. Lastly, the distance between initial cuts doesn't accurately describe the step over concept, as it is more about overlapping motions rather than starting points. Understanding step over helps in optimizing machining processes for efficiency and quality.