How to calculate the speed and feed for cnc lathe machining material

       Hello everyone, this is HANBS, I'm Sonya, I'm glad to share some knowledge about cnc or swiss lathe with you again, today I'm going to share how to calculate the speed and feed for cnc lathe machining material, in this article I choose to take brass as an example. In this article, I choose to take brass as an example. Brass is more stable and easy to cut, so it is more appropriate to take it as an example. If you don't know how to calculate the speed and feed rate when the machine is in operation, then you may want to follow the steps below:

1. Calculate the cutting speed (S)

Cutting speed is usually measured in feet per minute (FPM) or meters per minute (MPM). For brass, typical cutting speeds are about 300-600 SFM (surface feet per minute).

Use the formula:

Where:

D = Diameter of workpiece in inches

N = spindle speed in RPM

Or it can be rearranged to find N:

 

2. Calculate the feed rate (F)

Feed rates are usually expressed in feeds per revolution (IPR) or millimeters per revolution (MMPR). For brass, common feed rates are between 0.002 and 0.006 inches.

3. Calculate Total Feed Rate (FT)

The following formula can be used to calculate the overall feed rate per minute (IPM)

where:

F = feed per revolution (IPR)

N = spindle speed (RPM)

Example Calculation

1. Given:

Diameter D = 2 in.

Cutting speed S = 400 SFM (example value)

2. Calculate the RPM:

3. feed rate:

Choose F=0.004 IPR（example value）

4. Calculate total feed rate:

Summary: Spindle speed (RPM): approx. 764 RPM

Feed rate (IPM): approx. 3.056 IPM

       These values can be adjusted appropriately for your tool, machine capabilities, and specific brass alloy. But always consult the tool manufacturer's guide for optimum settings. The above knowledge is given as a reference.

       These formulas are suitable for most cnc lathe, but specific cutting speeds and feed rates may vary depending on the type of machine, tool material and machining conditions. It is best to refer to the machine tool manufacturer's recommendations and the parameters provided by the tool manufacturer for best results.

       This is what I have shared today, I hope it can help people in need. If there is anything you don't understand about swiss lathe or cnc lathe, we can discuss it. See you next time.