Regarding Potentionmeter

How do i go about selecting the knobs for potentionmeter?
Do i have to know the shaft diameter or spindle diameter?
What is a shaft diameter and what is a spindle diameter?
Please advise. Thanks.

I don't know what a spindle is, but the knob goes on the shaft and should be sized to fit. Common sizes for pot shafts are 1/4 inch and 1/8 inch.

Example: "The standard pot. is 15/16" in diameter and has a 3/16" diameter shaft. Never heard anything about a spindle before.
On the above you buy a knob for a 3/16" shaft. Also there are different types of shafts such as knurled or split or ones that are smooth like the ones that Radio Shack sells.

I prefer the knobs with setscrews, they stay put better..