Calculate radial depth of cut, diameter reduction, remaining diameter and estimated number of turning passes from starting and finished workpiece sizes.
Calculate to see the pass breakdown.
Enter starting and finished diameters to calculate.
How is turning depth of cut calculated? Subtract the finished diameter from the starting diameter and divide the result by two.
Why is depth of cut half the diameter reduction? Because turning removes material from the radius. Removing 1 mm radially reduces the diameter by 2 mm.
What is radial depth of cut? It is the distance from the original workpiece surface to the new machined surface measured toward the centreline.
How do I calculate the number of roughing passes? Divide total radial stock by the desired radial depth per pass and round up to the next whole pass.
What happens on the final pass? The final pass may remove the remaining stock, which can be smaller than the selected roughing depth.
Does a larger depth of cut always make machining faster? Not necessarily. Machine power, rigidity, insert capability, workholding and chip control can limit practical depth of cut.
Does depth of cut affect cutting force? Yes. Increasing depth of cut generally increases the cross-sectional area of material being removed and can significantly increase cutting forces.
Can I use this for CNC turning? Yes. It calculates the geometric radial stock and pass count. CNC toolpaths should still account for tool nose radius, finishing allowance, roughing strategy and machine limits.
Can this calculate internal boring depth of cut? The same radial geometry applies to boring when the starting and finished bore diameters are entered appropriately, but tool clearance and boring-bar rigidity must also be considered.
Does the calculator include a finishing allowance? No. It calculates the total geometric stock between the entered starting and finished diameters. A separate finishing allowance can be subtracted from the roughing stock if required.