NSK developed a series(S-Type)of tough, sealed-clean roller bearings for chain conveyors that must operate under severe conditions They feature newly designed seals (Japanese Utility Model pending) with exceptional effectiveness. These seals, combined with specially formulated grease, assure long life with no maintenance, even at high temperatures and in the presence of water and scale. Also, the inner and outer rings are made of case-hardened steel to make them resistant to shock loads for rugged operating conditions, S-Type chain-conveyor bearings are the solution to maintenance problems.