Bone nuts.

[Simon Barden]

I’ve made a few bone nuts from blanks now. I have an oscillating spindle sander and that makes light work of the bulk sanding. I get it almost to size on that and then use sandpaper on a flat surface to do the rest. Once you put your mind to it, it doesn’t take much longer than sanding a pre-bought nut down to size (they are rarely the right thickness or height).

Whether you can use a 43mm nut filed down at the ends on a 42mm wide neck really depends on how close the string slots are cut to the ends of the frets. There isn’t a universal standard. It’s normally about 2mm to the outer edge of the slot, but I’ve seen noticeable differences on guitars (I’ve worked on far fewer basses) from the same manufacturer. And pre-bought guitar nuts definitely have differences in the overall string spacing.

I have a small stock of replacement bone nuts of slightly different lengths and widths and heights, and even on nuts of the same length, I know the string spacing can be different. I’ve recently had to make my own nut for a Squier Tele neck where the slot was quite wide and on the only wide nut I had, the strings were slightly too near the edges once I’d taken 0.5mm off each end. It was too easy to push the low E string off the board when fretting chords. So that had to come off and a bespoke one fitted.

It’s probably best to measure the distance between the end of the nut and the string slot on an instrument you already have and like the feel of. If you can get the same distance at the ends after filing 0.5mm off, then you’ll be fine.

[Jetblack]

Thanks Simon,
I will certainly experiment with the blanks, though, not having the correct files will be a challenge. Any thoughts on what I may be able to use aside from the purchase of nut files to get a good finish ??? or should I bite the bullet and just get the files ??? I know I may never use them again unless I do another build or have to replace the odd nut in the future, so it's a bit of an expense learning kerb. Can't justify a luthiers cost to get them done either. I did have thoughts on using the old nuts as a template but that's simply not the way to go, the nut needs to be on the instrument in order to get the nut filed correctly.

[Simon Barden]

For bass nuts, you can normally use a combination of needle files. I have just purchased some Hosco bass nut files, but I was using needle files before that. I find the round one to be pretty good for lowering the slots, just using the tapered end of the file to get the right diameter for the slot - though you need to work from both sides otherwise the slot is too tapered.

Don't cut the blank so it's over-high, otherwise you'll be filing for hours and hours.

I have a cheap eBay string-spacing ruler. It's pretty much the same one as StuMac sell, but less money.

[Jetblack]

I have a set of fine needle files, but not very round, may get away with the E string slot but the rest are a lot finer than the files I have. So setting up the nut for height would require a set of feeler guages layed over the first fret ??? Then draw a line across the nut then sand down the nut till the height is matched before filing the slots ??? Ive looked at a few posts that seems to be the way to go ??? Ive also seen where blow torch cleaners have been used as slots files and are very cheap.

[Simon Barden]

On my needle file set, the flat file is 0.048” on the side dimension, which is fine for cutting a slot for a 0.045” G string. I’d always start smaller and expand the width, even with proper nut files, so that would be fine for getting all the initial slots cut, which will need widening on the E, A and D strings.

The nozzle cleaner files have been mentioned by others as OK for cutting bass nut slots, but the sets I’ve seen don’t have the diameters for cutting slots for the E and A strings as they only go up to 1.5mm diameter (which at 0.059” is slightly too small for a 0.065” slot.

You don’t need feeler gauges to determine a good starting height for the nut blank, just a ruler. Depth of the slot (or thickness of the fretboard for an end-of-board nut) plus 5mm (maybe 6mm for a 5-string). An 0.105” string is just under 2.7mm deep, so 5mm still leaves 2.3mm space above the board, which is more than enough for fret height and clearance.

Final nut height adjustment comes after you’ve done the final nut slot depth adjustments.

[Jetblack]

Thanks again for your help Simon, appreciate it.
ok my fret board comes in at 3mm to the center and 2.5mm to the sides, the nut blank is 6mm height fits nice and snug into the slot, so that leaves me with 3mm to cut the slots according the center and 2.5mm for the E and G strings, the blank has a radius and looks to be pretty close the neck radius, So im not sure if that will be enough height to cut and sit the strings in ?? Though it should be enough if I don't go too deep to start with, doing the 3rd fret and height check as I go, if go 1.5 mm deep for the E slot will that be enough to hold the string in position without it popping out or should I go to 2mm deep which will leave 1mm clearance to the fret board at the nut, seems like very low action, without doing anything at this point. It will be a fine line. Is the nut not heigh enough ???

[fender3x]

The nozzle cleaner files have been mentioned by others as OK for cutting bass nut slots, but the sets I’ve seen don’t have the diameters for cutting slots for the E and A strings as they only go up to 1.5mm diameter (which at 0.059” is slightly too small for a 0.065” slot.

I made a mess out of a blank with needle files. That may just be me. If I had better hand-eye coordination I would have learned the violin. (my mother thought I'd never have the dexterity for it...so...bass). I have found the nozzle cleaners to require a lot of patience, but with that proviso they have been darned near idiot proof on my bass nuts, at least for this idiot. BUT, you do have to search for the right set. Most are like Simon says. The biggest one is not very big. You can find bigger ones. I was lucky enough to find a set that was specifically for 5 string bass, so it had sizes that worked well for E, A strings. There's one for the low B string too, but I have never used it, not having a 5 string bass...

[Jetblack]

Fender3x, Your absolutely right, Ive made a mess of 2 blanks thus far with the needle files, I started with the triangle file so I could get the marks indented, quite surprised at how quickly that file bedded in, then of course using wider round files to try to get a rounded seat and of course keep that angle towards the tuner bases. Then using the nozzle cleaners for the other finer slots, 2 nuts in the bin, the others are in the "rethink" box. Ill now be semi patient and await the TUSQ nuts and keep practicing my Bass using the plastics.

[Simon Barden]

Use the edge of a flat needle file (providing your file is thin enough in that dimension for a G string slot). I’d certainly avoid the triangular file unless it’s just for scoring an initial line.

[Jetblack]

The triangle file was for scoring on the marked points, It was marked out really well with 5mm from E and G to the edge of the fret board then pretty much eyed in the 2 centre strings, just went a little too deep with the triangle file I really didn't expect it to cut in that quickly, I'm a bit heavy handed, but lesson learnt, I will take you advice and try again using the flat file and be a little more less heavy handed. Thanks Simon.