stone that I use for sharpening knives?

[JUAN DE PADILLA]

Hello, I´ve just bought a machine Tormek t-7, my question is this: in the videos in which jeff farris sharpens a knife and scissors, that type of stone being used?'s SB-250 or GS-250? grinding stone and when should I use??
thanks

[Jeff Farris]

That video is so old, there was only one stone at the time.    SG-250.  That is all I would use for knives and scissors. The SB-250 is for Stainless and harder alloys.

[JUAN DE PADILLA]

thanks
regards from spain