Ceramic hybrid ball bearings use ceramic balls. Ceramic balls weigh up to 40% less than steel balls, depending on size. This reduces centrifugal loading and skidding, so hybrid ceramic bearings can operate up to 50% faster than conventional bearings. This means that the outer race groove exerts less force inward against the ball as the bearing spins. This reduction in force reduces the friction and rolling resistance. The lighter ball allows the bearing to spin faster, and uses less energy to maintain its speed. Ceramic hybrid ball bearings use these ceramic balls in place of steel balls. They are constructed with steel (chrome steel GCr15 or stainless steel AISI440C ) inner and outer rings, but ceramic balls so they are known as hybrids.