Cibo FNF flap discs is a Zirconium oxide with a flat faced grinding surface! the fnf range is a great range to use for aggresive grinding on steel due to its premium abrasive cloth properties! 
its also safe to use on s/steel but is recomended to use with a faster rpm grinder!
available in 40/60/80/120 grit discs 
 
sold in packs of 10