Patent ID: 8661686

Claim:
A method of manufacturing a shell type needle roller bearing, said method comprising: forming a shell type outer ring by pressing; and arranging a plurality of needle rollers along an inner-diameter surface of the shell type outer ring, wherein said forming of the shell type outer ring by pressing consists essentially of only one drawing operation and only one ironing operation, the only one ironing operation being carried out simultaneously with the only one drawing operation, wherein during the ironing operation, a lubricating condition on an outer-diameter ironed surface which becomes an outer-diameter surface of the outer ring is a substantially fluid lubricating state, a punch for ironing is kept in sliding contact with the inner-diameter surface of the shell type outer ring and the inner-diameter surface of the outer ring is lubricated to a lesser degree than the outer-diameter surface of the outer ring such that a degree to which the inner-diameter surface of the outer ring is in contact with the punch results in the outer ring sliding relative to the punch as the outer ring moves through an ironing die, whereby a surface roughness of the inner-diameter surface of the outer ring is finer than a surface roughness of the outer-diameter surface of the outer ring as a result of the outer ring sliding relative to the punch, and wherein the shell type outer ring is made of casehardened steel.