Durable standard abrasive of silicon carbide. Available Sizes; 150mm & 178mm Available Grit: 16, 24, 40, 60, 80, 100, 120 Bona 8100 is a standard abrasive made of silicon carbide, also known as carborundum, a very hard mineral that creates new sharp points when worn. This ensures that it remains robust throughout its lifetime. This property - and an open coat - ensure cool running on high speed machines, such as edge sanders.