A roller bearing cage is disclosed, which is provided inexpensively from
basic minimum quantity of row material. The roller bearing cage is made
with a production method using rolling operations, which is the absence
of the formation of chips, while ensuring the strength and stiffness of
the cage. A circular inside surface of the cage is made to give an
advantage to the rolling operations. The circular inside surface is
circularly recessed to have a concaved surface of just one radius of
curvature R. A diametral dimension across diametrically opposing bottoms
of the circular recess is made larger than the pitch circle distance
P.C.D. Pillars of the cage have inside retainer lips, which are hard to
make any engagement with their associated rollers, which might worsen the
engine performance.