30309 (DIN720, ISO355);
7309A (GOST 27365-87)
The bearing consists of two rings (inner and outer) and rolling elements (tapered rollers) which are connected by a cage. The inner ring with a cage and rolling elements is a CONE. The outer ring is a CUP.
Tapered roller bearings are designed to accomodate combined loads (radial and axial). They have a split construction: the inner ring with the rollers and separator create the unit which can be mounted separately from the outer ring. This is a metric tapered roller bearing.