A. Independent laboratory testing has shown CentriFuse® Drums to be the most durable and longest wearing drums available. Their advantage comes from a composite construction employing a steel outer shell fused to a braking surface of patented high-strength cast iron. In a unique foundry operation, molten iron is poured into the rotating steel band to achieve a metallurgical bond between the two materials. After processing into a finished drum, the steel exterior provides high fatigue strength to avoid cracking in service, while the specialized iron offers unexcelled wear resistance. User claims of 2 – 3 times the life of cast drums are common, and drum fractures are virtually eliminated, leading to 80+ years as North America's premium commercial vehicle brake drum.