Specifications：
　1) Sliding contact surfaces: Steel vs. Steel.
　2) Materials:   Both outer race and inner race are made of high chrome bearing steel.
　3) Heat   treatment: Both outer race and inner race are quenched (hardened), surface   phosphorized.
　4) Features of structure: With oil groove and oil holes, with   an axial split in outer race. With dual seals.
　5) Lubricant: molybdenum   disulfide.
　6) Properties: Heavy duty, good wearability, corrosion resistance,   self-alignment, dust proof.