By User10805

April 23, 2023, 1:31 am

Thread mill RPM and resulting Feed

Hi all,

Problem scope

We are trying to cut M3 threads. Tool is this (2.35mm tip diameter, 0.5mm pitch):


which is basically like a twig...


The default RPM in Fusion360 is 5000 which does seem to work well with feed of about 300mm/min

1. But HSMAdvisor seem to recommend going to my set max at 20000RPM (generic Chinese spindle tops out at 24000RPM). Is this OK?

2. Is it also normal that when I reduce the shank diameter for thread mill, the feed goes up?


tool Screenshot 2023-04-23 114533.png thread mill values Screenshot 2023-04-23 115307.png solid end mill values Screenshot 2023-04-23 115425.png

cant leave messages here
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Eldar Gerfanov (Admin)

April 24, 2023, 12:27 am


1. I can't tell you whether 20000 RPM is too high or too low because you didn't specify the material you are machining.
Cutting speed-wise, calculations should be almost the same as for sold end mills.

2. When you reduce the shank diameter, HSMAdvisor reduces the suggested WOC, which in turn allows for increasing the feed rate, due to the reduction of engagement....
To prevent that from happening manually enter the DOC and WOC values:
DOC = height of the teeth. in your case that would be 0.5mm
WOC= (thread_dia - pilot hole) / 2

Please see below for the suggested tool setup.
(The latest HSMAdvisor v2.6.6 shown)

Thread mill RPM and resulting Feed-1.PNG Thread mill RPM and resulting Feed-1.PNG


April 26, 2023, 8:05 pm

Thank you for your reply, I'm cutting 6061.

I should have read the other thread first:


Think I have most things figured out. Just wonder in the other thread, it's obvious that the DOC and WOC is kinda fixed for thread milling operation. In that case, why doesn't HSMAdvisor recommend those values?


Eldar Gerfanov (Admin)

April 26, 2023, 8:24 pm


DOC and WOC are not not necessarily fixed.

There are thread mill types that so not require a pilot hole, so WOC for the would be 100%

Likewise if you are using multiple -tooth threadmill, then the flute length will not equal the pitch and DOC will be different.

Also there is external thread milling that does not require a pilot hole at all.

Best regards.



April 26, 2023, 8:48 pm

Perfect! :)

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