Another homemade nut file

[Steve Williams]

I thought this needed more views than it has received.

http://www.youtube.com/watch?v=GwyQ8srzEz8

[Keith Somerville]

Hmmm. Might do in a pinch for the larger slots, but looks like it makes heavy going on that scrap wood. You need teeth that cut, not just chip bits off.

[Brian Adams]

I make them from feeler gages as well, but by dragging the edge across a good fresh flat mill file, following the file's tooth grooves. I drag to and fro, many times, letting the blade lag and roll a bit changing directions, so the resulting teeth wrap around the edge a bit, but are much shallower and have no kerf, so the resulting slot is pretty much exactly the width of the feeler. It cuts bone or plastic slowly, leaving fine dust, but I only use them to make final fine adjustment to slot depth, or to correct the break angle on an otherwise good slot.

This hammered type seems like it would make a wider than nominal slot, due to the overhanging "kerf" the chisel appears to leave.

[Murray MacLeod]

Not that I have ever made nut files out of feeler gauges (nor have any intention of ever so doing)    , but if I were ever to contemplate doing so, it seems kind of axiomatic to me that it would be far more effective to clamp the six gauges ( or whatever number you want) into the vice all at once, and use a jeweller's file to notch the teeth, instead of doing one at a time  using a hammer and chisel, which will almost certainly result in massive deformation of the thinner blades.

If you are going the home-made route, then guitar strings of appropriate gauge in a metal frame under tension will cut nut slots effectively for the wound strings,  but StewMac nut files do the job even better.