Correct.
The angle of the twist also determines the diameter that is cut.
If you don't get it right they don't cross at 45 degrees but in many cases it's not noticable.
The knurls wheel really need to be recessed with top hatted axles so you can get as close as possible to shoulders.
looking for a link to the wheels but gotta post this as need to shut down, relad the latest flash and reboot.
I have to do this about 3 times a week Adobe like Norton wants listing as a virus.
Come back to edit in a bit.
Page 388 in the J&L catalogue, bottom of the page are two side knurling tools, these are the wheeels you want.
The wheels are on page 389 down the bottom, type 5.
There are some TiN coated ones for pig farmers with deep pockets on a previous page.
http://www.mscdirect.co.uk/CGI/INPDFF?PMCTLG=00&PMPAGE=387&PMITEM=BMK-42080MNo idea what they are like, us mere mortals can't afford these.