MIMF

Why is the nut on a classical guitar typical about 5mm wide and not 2.5mm or 3mm like a saddle? Currently I have a 2.5mm nut on a guitar I am finishing as I have not finished the nut slot - works fine.

The only reason I can think of is that a longer ramp from the tuners is somehow beneficial. Any other theories? Many classicals in the past as well as gazillions of other guitars have a zero fret so it can't really have anything to do with the sound as such.

Ideas, theories?

I don't know, and I don't particularly adhere to the 5 mm thickness of the nut. Most of mine, which are tapered, are about 4mm in the center, so go from approximately 4.2 to about 3.8. Just enough taper to keep them tight in the slot, which is tapered to match.

Thanks Waddy. I am not too bother about the exact size either but it tends to be in the 5mm range as that seems to be the typical area for ready made nuts or for bone blanks. Curious why this is the case. I have never seen an explanation.

Because it's tradition. And there is not an overwhelming reason to change.

Mine are the same thickness as the file I use for cleaning out the slot between the fretboard and the head stock veneer. I can't think of a more practical reason than that. I'd be fine with zero frets too, but most players would probably think they looked funny. I can't think of a good argument for CG nuts to be any particular thickness.

It's also possible that the wider nut (than saddle) when properly made provides greater bearing surface and wear resistance than the saddle. The saddle performs a different function and being thinner allows it to perform that function better, at the expense of some wear resistance (saddles are usually made to be easily replaced).