I don't have much to say other than: man, they suck. Like trying to make a nut out of a bar of soap. However, the customer is always right... apparently. :D
what do you mean by "teflon nut"?
are you talking about the graph-tech stuff where the plastic-whatever material has teflon in it?
those work fine but yeah, kinda soft; they make a nice glassy ringing when you drop them on a hard surface but file like soft plastic.
since allparts has started carrying pre-machined and slotted nuts from actual bone for like 1/3 the price i've pretty much stopped bothering with graph-tech for my pre-cut nut installs.
there are a couple of types of nuts that are either straight Delrin which is a hard industrial bearing material (also a softer grade is used for plectrums) or PTFT impregnated Synthetics such as Graph Tec which are a common nut material used throughout the industry.
We have used Delrin from time to time to solve hang ups in awkward designed headstock configurations which are used under duress such as deep bending. These situations become a trade-off between losing (maybe ) some tone or just plains straight being out of tune all the time. Big string spreads at the nut like Gretschs are particularly troublesome and the use of a PTFT nut goes along way to getting them to play in the rock genre (along with a whole bunch of other stuff at the Bigsby end).
The PTFT nuts are fine for heavy duty playing environments and as I've said elsewhere, bone is fine and lots of the old guys love it, but its nothing special these days and while I'm sure it lasts a bit longer and you can charge more for it, we take the position that using what is best for the player and what he's doing is more important than having just one option.
Interestingly, and related is the use of PTFT loaded saddles to minimise string breakage for the heavy handed players. We do this a bit and also use the PTFT saddles in the piezo loaded Graph tech Resomax bridges. Nothing really negative in this environment and wear rates are not anything for general consideration, They wear faster than steel saddles but don't seem to have much noticeable effect on the overall tone, just a little smoother across the spectrum and they also do what they say they do in minimising string breakage under load and also minimising corrosion at the string saddle junction due to less galvanic interaction. Just general knowledge about the different options and technology based solutions that we should all be aware of.
It was actually a material supplied by the customer, who called it Teflon. I've never used it before, to be honest. Nothing like Graph Tec (which I like) or any other plastic I've come across. Just seemed to be a small brick of white Teflon: very hard to file slots into and shape, because it seemed to immediately load the file up which would then skid off the surface. But it was quite hard, not terribly bright sounding, but seemed durable enough. It left everything feeling quite greasy. I was going to ask where it had come from, but never had the chance. I'll see if I can find out more!