Parting-off time estimates how long it takes to cut through stock using a parting (cut-off) tool, based on the radial distance the tool must travel and the parting feed rate.
How it works
The parting tool travels from the outer diameter toward center, or toward a hollow bore/bar diameter on tube stock, so travel distance is half the difference between stock and bore diameter, not the full diameter. Parting feeds run slower than normal turning feeds because the tool is narrow, has poor chip clearance, and is prone to grabbing if fed too aggressively.
FAQ
Why is my parting tool grabbing or breaking? Common causes are feed rate too high for the tool width, excessive tool overhang, inadequate chip evacuation, or tool geometry not matching the material. Slowing the feed rate near the center, where surface speed drops, often helps.
Related Guides
CNC Calculators · OD Turning Time Calculator · ID Boring Time Calculator