Here is a machinist type reference, likely with much more information than desired :-)

http://www.reed-machinery.com/wp-content/uploads/2019/04/knurls-and-knurling-tech-data-master.pdf

I think that if a person is going to boolean away the "grooves", that their size must match up with the circumference, to avoid a discontinuity...

- Brian

It looks like some of the tools move the metal, rather than machine it away...(probably not a desired CAD method.)

No more time to play today.

Something I was working on in the Node Editor a while back.

Hi,
try this.
Create star shape in custom mode and extrude.
Add a twist then mirror object and boolean union.
Cheers
Barry

Hi all.



https://yadi.sk/d/XmSJGQKFSs1nhw