This is a borderline obsessive tangent from the saw sharpening critique/input thread.
Here are close-ups of the tips and tangs of 5 types of needle files that I have on hand. From top to bottom: Grobet USA, Grobet Swiss, Glardon-Vallorbe, Nicholson, Bahco. The Nicholson and Bahco files are 6", the others are all 7-7/8".
IQ8I0852.jpgIQ8I0851.jpg
A few remarks: All but the "Grobet USA" are Swiss made. We know that the "Grobet Swiss" and "Glardon-Vallorbe" files are the same file from the same UMV factory. The Nicholson has identical knurling, toothing, and (scaled down) profile so I think it's a near certainty that one comes from UMV as well. The Bahco is identical to the Nicholson in every respect except knurling/engraving, so I think it's a safe bet that's also a product of UMV. In the Otto Frei video that Stewie posted in the other thread they claim that all needle files manufactured in Switzerland come from UMV, and finally I can't tell any difference among the four in terms of performance.
The Grobet USA file is made in Italy, and has noticeably different surface color/reflectivity, different toothing, and a less "full" tip profile with a blunt point. From past experience I suspect it's actually a Corradi, though I don't have one of those on hand to compare to at the moment. In terms of performance it's right up there with the others. IMO it's less smooth and finely finished than the Swiss contingent, but the steel may be a bit harder.
So the bottom line is that for needle files basically all of the "big name" brands except Grobet USA end up being the same thing, and they're all at least decent.
EDIT: One other point of similarity between the Swiss files: The shafts of all 4 were turned at the same feed rate (you can see the machining marks very clearly in the full-res images, and moderately clearly in the downscaled SMC versions).