
 1) Sliding contact surfaces: Steel vs. PTFE fabric.
 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),
 outer race surfaces are phosphorized, inner race surfaces are plated 
with chrome.
 4) Features of structure: Without oil groove and oil 
holes, with an axial split in outer race. With dual seals. Sticked with a
 piece of PTFE fabric on inner surface of outer race. 
 5) Properties: Self-lubricated, low friction, good wearability, corrosion resistance, self-alignment, dust proof.
