
 1) Sliding contact surfaces: Steel vs. PTFE sintered bronzed mesh.
 2) Materials: Outer race is made of carbon steel, inner race is made of high chrome bearing steel. 
 3) Heat treatment: Without heat treatment on outer race. Inner race is quenched (hardened), and surface plated with chrome.
 4)
 Features of structure: Without oil groove or oil hole. Outer race 
formed by extrusion. With a PTFE sintered bronzed mesh between outer 
race and inner race. 
 5) Properties: Self-lubricated, good wearability, self-alignment.
