Printing cylinder for offset printing

A printing cylinder for offset printing comprising:

• a cylinder member of a hollow cylinder having a covering portion which forms a substantially uniform, smooth outer circumferential surface having no spliced portion in the circumferential direction, the covering portion being capable of transferring printing images onto an adjacent printing cylinder or printing paper in contact with the covering portion;
• and
• printing cylinder support means including a pair of support shafts which are supported on opposed frames such that the support shafts are rotatable about a common axis, the support shafts each having a shaft end portion which is connected to an end portion of the cylinder member via an engagement portion and by use of connection means, wherein the engagement portion includes a groove and a ridge portion, one of the groove and the ridge portion being formed on an end surface of the cylinder member such that the one of the groove and the ridge portion extends in a radial direction from the circumferential edge to reach the center of the end surface, and the other of the groove and the ridge portion being formed on the shaft end portion of the support shaft located at the inner side of the corresponding frame, the other of the groove and the ridge portion extending in a radial direction from the circumferential edge to reach the center of the shaft end portion, wherein the ridge portion has a shape corresponding to that of the groove.