Method and apparatus for overmolding a gear onto a shaft

A shaft (110) for receiving a polymer overmolding of a gear (22) from an axial single-gate mold. The shaft (110) is provided with a plurality of features for preventing rotation of the molded gear on the shaft, the features being in the form of axial-direction flats(114a, 114b, 114c, 114d, 214a, 214b, 214c), the number of such flats being greater than the prior art two (double D) and preferably four (quadral D). In a four-flat mold and shaft arrangement having a single, axial mold gate, longitudinal knit lines between the quadral D's are virtually non-existent, and polymer in these regions is substantially as strong as polymer elsewhere in the casting.