All our knobs are for USA spec pots unless the discription says they are metric which means that they are for split shaft pots that have 24 splines and are approx 6mm diameter or solid shaft which are 1/4" (6.43mm).
"I have counted the splines on my pots and there are only 10 per side". Yes but what you are missing is that there were 24 before the the slot was cut so you may have 10 or 11 per side.
Let's talk about the difference between Fender and Gibson style knobs.
Fender knobs are smooth inside and about 5.8mm internal diameter and made of a softish plastic so you can push them on and the metal splines on the pot cut into the knob...easy peasy.
Gibson knobs are made from a much harder material where this is not possible so they are moulded with the reverse of the splines in place. Tolerances in the production of the pots, whether the shafts are brass or aluminium as well as tolerances in the moulding of the knobs and shrinkage after cooling mean that the knobs, though the correct size, can be a little tight or loose so if they do not easliy press on what should you do.
DO NOT USE EXCESS PRESSURE TO FORCE THE KNOBS ONTO THE POT.
This can damage the pot and cause the back to come off causing all kinds of problems. Take a old pot and wipe some lubricant onto the splines. This can be bees wax, dry soap, a squirt of WD 40. Then press the knob onto the shaft and then pull off and reapeat and you should find that each time it goes on a little further.
This does take a little time but stick with it, do not be tempted to squeeze the tabs together as the shaft material is hard and brittle and the chances are that one of the tabs will snap off or only one will bend and then the knob will be crooked.
If the knob is loose then you can take a large flat head screwdriver, as used to adjust a Fender truss rod, and press into the slot gently (see above) as you only need to open by 0.01mm to get e good fit. Press gently then try the knob as you don't want to go too far.
If in doubt please contact us before you damage your guitar or the knobs
