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.