4 masonry sandstone GRIT 30 stone 54 concrete floor grinder pad polisher admin September 21, 2024 masonry concrete, floor, grinder, grit, masonry, polisher, sandstone, stone 54 X Grit 30. 3.2mm thickness. Recommend 2500 – 5000 rpm. Wet or dry use (wet use recommended). ← Previous post Next post →