TOT radial spherical plain bearings requiring maintenance (steel -on steel) have hardened sliding contact surface on both rings. The surfaces are treated with molybdenum disuphide and phosphate. It has characterisdics of wear-resistance and wear-corrosion. Bearings with this sliding contact surface combination require regular relubrication. The high strength of the sliding contact surfaces make these bearings, especially suitable for bearing arrangements where heavy loads of alternating direction, shock loads or heavy static loads have to be accommodated.