In general, pots come in two standard styles, knurled, and solid shaft
Knurled (Split shaft) is a star polygon pattern that uses press on knobs
Solid Shaft is as the name sounds, a solid circular shaped shaft that uses a tightened screw to attach a knob
18 tooth coarse
Knurled Shaft:Fine or coarse?
If you are not sure which one you have just count the splines!
Coarse:Tends to be the most common as it is used on most import brands likE, Bourns, CGE, etc.
Fine: Is fairly easy to figure out as CTS tends to be the only brand to use this pattern.
24 tooth fine
This comes standard on most imports including Made in Mexico guitars. It’s Just slightly smaller then the US spec style so if you are using 1/4th knobs you will need a shim to help with a perfect fit.
SOLID SHAFT: 6MM OR 1/4TH?
WHEN CHOOSING KNOBs MAKE SURE TO GET THE RIGHT SIZE
This standard size is what you find on most American guitars. Larger then the import style it requires that if you are changing to US from Import, that you have a 1/4th sized knob.