View Full Version : Cutter diam and surface speed to RPM calculator

08-27-2010, 03:49 AM
There has been a lot of discussion over time of the cutter speed (RPM) and feed rate (inches per minute) for various tool and job materials combinations.

I saw this one and thought I'd pass it one - as one of many - that addresses these issues and may be of help:


Use this as guide or starting point only as the job, cutter and machine requirements will largely be determined by the state of the cutter, the rigidity of the machine (mill) and the set-up of the job.

It should be better than "rules of thumb" and wild-ar$ed guessing.

bob ward
08-27-2010, 06:17 AM
Thanks oldtiffie, those charts are a useful size for printing and taping on a spare vertical surface

Forrest Addy
08-27-2010, 09:27 AM
That's a good one.

08-29-2010, 03:26 PM
Has anyone seen comprehensive speed and feed data for various plastics, like PVC, nylon, Teflon, Delrin (acetal), Lucite (acrylic), and Lexan (polycarbonate)?

I've found the odd bits of info for individual plastics but nothing comprehensive.


08-29-2010, 07:29 PM
thanks for that link,gives me a great starting point as i am just starting out machining...:D
cheers Tom....

08-29-2010, 08:54 PM
Here is a link to a feed and speed calculator, I use this one all the time. Best and most safe method is to use chip loading, use the mfg's recommended surface feet, common sense and spindle speed.
Note: Cimco edit calls chip load> Feed per tooth (Sz)


08-30-2010, 03:17 AM
Pity it is imperial :(

08-30-2010, 04:02 AM
Its all too easy to plot a series of graphs of surface speed vs RPM - for each cutter type and material if needs be.

Pads of A4 graph sheets are pretty cheap - and very handy for plotting lottsa stuff.

Graphs, tables and software are only approximations anyway and so need to be used with caution so the degree of accuracy needed is not at all high.

08-30-2010, 12:45 PM
Pity it is imperial :(
Just click on units and select metric.