Stock Diameters for Even Knurls
Knurls have a definite pitch, and they work best when the stock circumference is an approximate multiple of that pitch. Here is a calculator and an easy formula to find the next smaller diameter from the diameter of your work piece. The most material you ever have to remove is 0.023" for a 14-pitch knurl.
The pitch factor is simply the pitch multiplied by pi.
If you have Excel, here is a little spreadsheet that will calculate it all for you:
The formula in cell C4 is =ROUND(INT(A4*B4*PI())/B4/PI(),3)