I had no issues withhttps://www.amazon.com/10-Pack-Density-Zirconia-Grinding/dp/B079Q4T2JY/ref=sr_1_7?hvadid=78615134470790&hvbmt=be&hvdev=c&hvqmt=e&keywords=sanding+discs+36+grit&qid=1563575183&rnid=2941120011&s=industrial&sr=1-7
these discs.
Also bought in 6" that fit my 4" grinder. Cleared a nice path.