PURPOSE: To readily assemble a bearing having short size in the axis direction without including a cage by allowing two opposing lateral shoulder-forming detachable spring rings to hold a roller.

CONSTITUTION: Ring-like grooves 15 and 16, and ring-like channels 17 and 18 are formed on the opposite surface to an inner edge part 5" of an outer race 5', and tilted ring-like protrusions 19 and 20 are formed. Spring rings 13 and 14 are snap-inserted into the ring-like grooves 15 and 16, and the ring-like protrusions 19 and 20 are pushed on the flat ring-like press edge parts 25 of protruded teeth 26 at the outer periphery parts of the shoulder-forming spring rings 13 and 14 by a press molding mold and locked.