I use a GRS power hone to sharpen my gravers. Haven't tried tungsten. I usually use carbide or hard steel. But it all depends on the stock. There seems to be a divergence of opinion on how hard (temper) a balance staff should be. Trying to re-pivot a broken staff suggests that, most of the time, the steel is pretty hard, so you need correspondingly hard gravers.
Dont have much experience yet but it seems to be an excellent stuff. It is however really fragile! I dont know how it is called when the working piece catches the graver and grabbing from my hand, the cutting edge chips. It chips also if the graver slips from the piece. So great care must be taken to avoid hard pushing and one has to concentrate on the angles at any times. For this the graver must be really-really sharp. Sharpening on the contrarily is a real headache. Dean DK has a great video how to do it. My method is however different and maybe i will show it next time.
One also need a square graver to be able to maintain the same angle every time. Sadly, i have only this big graver in square, the other tungstens are round.
I plan to buy a smaller square (2.1mm) from GRS tools. It costs 13 CHF shipped to our country.
But this weekend i will make another attempt to turn this balance staff finally This is a friction fit balance so no need to make an undercut in the balance shoulder for which i would need another graver grinded with smaller angle.
Beautifully sharp graver. I always struggle with getting those straight lines when sharpening.
How well does Tungsten work? It's never occurred to me to use such a graver but Tungsten is hard as hell and holds up under heat. Are they a pain to maintain?