This single row deep groove ball bearing carries the reference 6218-C4, with a bore diameter of 90.0 mm, outside diameter of 160.0 mm and width of 30.0 mm, weighing 2.189 kg. It is fitted with a steel sheet metal cage (JN) and features C4 (Group 4) radial internal clearance, allowing operation with limiting speed up to 6300 1/min and reference speed of 5100 1/min. Bore type Z applies to this variant. Dimensionally and constructionally equivalent to SKF 6218/C4, NSK 6218C4, and NTN 6218C4. The C4 clearance class compensates for thermal expansion and shaft fit tolerances under load, making this bearing suitable where operating temperatures or interference fits would otherwise reduce internal clearance below normal range. The steel sheet metal cage design supports the stated speed ratings while keeping mass low relative to size. As an open-type bearing, external lubrication and sealing arrangements must be provided in the housing to match operating conditions and speed requirements.