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For an acoustic guitar that will play both lights (12's) and mediums (13's).

What size nut slot (file gage) do you use?
- The same as the largest size string gage to go in to the slot?
- .001" larger than the largest size string gage to go in to the slot?
- ____ larger than the largest size string gage to go in to the slot?

What is the maximum amount that you can oversize a nut slot and still have it acceptable? (Can you set up a nut to handle Heavy gage strings (14"s) and still have it work fine for Light gage too (12's.)

Ed

Hmm - let me see if I get the right answer on this one. (Pros, set me straight if I'm off).
You certainly don't want the nut slots too snug for the strings, or tuning it will be impossible, and you'll wear/break strings prematuresly. I'd shape it so that it's an appropriate fit for the larger gauge strings and it tunes nicely for those. That shouldn't provide too much slop for the lighter gauge ones.

Different opinions?

The best way to think of this is to ask yourself "what happens if"

If the slot is slightly over sized the only problem accures when bending strings. The string could move side to side in the slot not really a big issue.

now a slot that is too tight creates tunning issues. The string binds in the nut. I have built many guitars for clients that used .054-.012 but slotted .056-.013 so that the client could use anything with in that range.

Corky, the key question I'm asking is: what is "an appropriate fit" measurement number. Its obvious that we all have a goal to "shape it so that it's an appropriate fit", but what diminsion (number) of excess slop is appropriate? What number is "too much slop"? Is a .052" (light) string in a .059" (heavy) slot appropriate?

Also, what is too tight? Is a .056" (medium) string in a .056" slot appropriate? Or should there always be some extra clearance? If so, how much? .001"?

What tolerance numbers are people using?

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Considering that most nut slotting files aren't that accurate to begin with (plus the lack of precision of the guy using them), I would say that there's no problem going as far as .010" tolerance for the wound strings. I might be wrong though, but I haven't experienced any particular problems within that .005 to .010" range.

There's not much input here, and yet surely most builders have some toleance goal for nut slot width.

Look's like, so far, we have:

1. a vote for .004" maximum greater than string gage
2. a vote for .010" maximum greater than string gage

Does anyone else have anything to add here?

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Thanks for the help, Tony.

Actually I have tried on numerous times to use the search feature. It is either me not knowing how to properly use the feature, or the feature is very weak. If I type in "nut slot" I get a ton of hits with the vast majority being irrelevent. And the hit can have only one of the words instead of both as I would prefer. Surely there is some way to set the filter to require BOTH words to be included in the hit, but I don't know how.

If I type in "nut" I get absolutely zero. It shows no hits.

If I type in "+nut+slot-bridge-fretboard" I get a little better, but still a bunch of unrelated stuff.

Any advice for searches?

Regarding the nut tolerance, if I read you correctly the nut slot should be one size greater than the largest string planned to be used in that slot. Correct? So this means that each slot should be .001" largest planned string since nut files can be obtained about every .001" size. Correct?

Are you saying the maximum nut slot size should be no more than .004" than the smallest string you plan on using in that slot?

If I understand you, then, for exampe: playing heavy strings .059" would get a .059 + .001 = .060" slot. Then the smallest string you would recommend playing would be .060 -.004 = .056" which is a medium string. But a light gage string at .052 is .008" smaller than the slot which you would not recommend using. (Whereas other folks with a .010" tolerance would say it is fine.)

I'm just trying to learn from others' experience; what they have done that works and what they know that does not work.

Thanks again for the help. I hope I understood you correctly.

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Tony, you're the man. Thanks so much for taking the time to help me. I really do appreciate your generosity.

By the way, I have clue as to what "Kia ora" means. I assume that it is a greeting of sorts. At first I thought it was a response to my comments about my ineptness in using the search feature.

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I'm surprised so many people can get away with using oversized slots without buzzing. I try to get mine dead on.

Just now, after messing with a low E slot that was .002" too wide (at most) and buzzing on the sides of the slot, I tried something completely different and used a triangular needle file. It looks odd because you can see light in the V under the string but there isn't a hint of buzzing and it tunes very smoothly. Only headache is you can't file to a line since the point of the V goes well below the string. You just have to chase it down a bit at a time. This is a guitar I'm hanging on to for awhile so it will be interesting to see how it wears. So far, so good.

Anyone else tried this?

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