Ruby Grain grinds finer Camel Grinding Wheels offers a line of ruby surface grinding wheels for fast material removal and strong form-holding capabilities. Ruby aluminum oxide grain is a tough, sharp, friable abrasive engineered for grinding all tool steels, including steel with high levels of chromium. Designed for fast material removals and reduced cycle times, ruby wheels increase productivity and require fewer dressing intervals. In addition, ruby grain is a tougher abrasive compared to other forms of oxide. CGW ruby surface wheels are 7" to 14" in diameter.