Definition
A tool path is the sequence of moves the tool makes to cut a shape: the cutting moves, the lead-in and lead-out moves, and the rapid moves between two cuts. The path follows from the strategy the programmer chooses, for example layer-by-layer pocketing, contour following, or keeping the tool's engagement with the material constant.
What it means for the calculation
Two programmers can reach very different times on the same machine with the same tool. The path decides how much of the time is spent actually cutting and how much is spent moving through air. A deep, narrow pocket forces a long, thin tool, and that calls for lighter cuts and therefore more passes. The programming itself belongs in the calculation too: a difficult path costs hours before the machine runs, and those hours land on the first order.
Where this comes up
Not on the drawing. The path is a work preparation choice, not a customer requirement. The drawing does steer it: corner radii, wall thicknesses, the ratio of depth to width, and the roughness requirements together decide which paths are possible.
Common mistakes
Estimating machining time from removed volume alone, as if the path played no role. Also forgetting the programming time on a one-off, contoured part, where on a single piece it sometimes weighs more than the machine time.
Two programmers can reach very different times on the same machine with the same tool. The path decides how much of the time is spent actually cutting and how much is spent moving through air. A deep, narrow pocket forces a long, thin tool, and that calls for lighter cuts and therefore more passes. The programming itself belongs in the calculation too: a difficult path costs hours before the machine runs, and those hours land on the first order.
See how Blake reviews a partFrequently asked questions
Does a different path change the shape of the part?
No, but it changes the time, the tool wear and often the surface quality.
Why does a small corner radius cost extra?
Because it forces a smaller tool, and a smaller tool removes less per pass.
Does programming time belong to setup time?
It is usually priced separately, because it falls once per part, not once per order.