Engineered for internal mechanical applications where external contamination is not a factor, the 6918 is a premium open-type deep groove ball bearing. Featuring an unsealed, shield-free architecture, this bearing offers absolute zero seal friction, allowing the internal rolling elements to interact directly with oil-bath or circulating lubrication systems. This unrestricted flow makes the 6918 the ultimate choice for large-bore (90mm) applications requiring superior thermal dissipation and ultra-smooth rotation, such as heavy industrial transmissions, machine tool spindles, and aerospace components.