Definition
Feed rate is the rate at which a cutting tool advances into the workpiece, typically expressed as distance per revolution or per minute. Together with cutting speed, it determines chip thickness, surface finish and cycle time, and like cutting speed, it is chosen based on material, tool and desired outcome rather than fixed by the machine.
Why feed rate differs between roughing and finishing
A higher feed rate generally cuts faster but produces a rougher surface finish and higher cutting forces, which is why feed rate is often reduced for a finishing pass even though it was set higher for roughing the same feature.
Where feed rate is implied
Not on the drawing directly; a required surface finish or tight tolerance implies a lower finishing feed rate, even though the feed rate itself isn't specified by the engineer.
Common mistakes
Using the same feed rate for roughing and finishing passes; a rate appropriate for quickly removing bulk material is usually too aggressive to hit a fine surface finish or tight tolerance on the final pass.
A higher feed rate generally cuts faster but produces a rougher surface finish and higher cutting forces, which is why feed rate is often reduced for a finishing pass even though it was set higher for roughing the same feature.
See how Blake reviews a partFrequently asked questions
Is feed rate the same as cutting speed?
No, cutting speed is how fast the cutting edge moves through the material; feed rate is how fast the tool advances into it, and both are set together.
Why does a finishing pass use a slower feed rate?
Because a slower feed reduces cutting forces and surface roughness, which is needed to hit a tight tolerance or fine finish.
Does feed rate affect tool life?
Yes, an excessive feed rate increases cutting forces and heat, which can shorten tool life alongside cutting speed.