Vast plumbing knowledge and expertise goes into every Superior Tool tube cutting wheel we make. Superior Tool's proprietary SXT cutting wheels use a special annealed steel that provides a higher carbon content for deeper, uniform hardening capabilities. We painstakingly burnish the wheel's cutting edge to ensure smooth, quick tubing cuts. Wheel edges are laser inspected for accuracy and quality. Each wheel is strengthened from hub-to-edge by cryogenic treatment and careful, slow tempering. A specially applied black oxide treatment reduces friction and fights corrosion. Package contains two replacement cutter wheels.