Mac Black Ceramic Honing Rod with Grooves 10.5 inch Mac Black Ceramic Honing Rod with RobThe Mac Black Ceramic Honing Rod is an extremely hard 81&deg; Rockwell compared to metal rods (steels) at 62&deg; and white ceramic rods at 76&deg; 1200 Grit. Black ceramic harder than white ceramic harder than steel. &bull; 1200 Grit Blade Length: 10.5 Inches