Abstract: A male mold member includes a base or body having a central projecting core with an intermediate peripheral tapered seat between the core and body. The body, seat and core are intercepted by a plurality of cylindrical bores spaced uniformly about the male mold member and inclined toward the core axis. The bores receive core blades having cylindrical bodies. The core blades are exteriorly shaped in the area of the core to form sections which continue the contour of the core and seat. The blades may each have a thread matrix in the core area. After molding, a stripper bushing, engaging the molded product, pushes the product along with the core blades to a position at which the core blades are collapsed so that the product may be stripped. In the molding position the stripper bushing has a tapered bore opening which fits snugly against the tapered seat portions on the blades to orient the blades to proper position and immobilize them.