1) Sliding contact surfaces: Steel vs. PTFE Fabric.
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 fabric between outer race and inner
race.
5) Properties: Self-lubricated, low friction good wearability, self-alignment.