Ribs should follow the proportional thickness guidelines shown below. If the rib is too thick in relation to the part wall, you may experience sinks, voids, warpage, weld lines, and longer cycle times. Position ribs in the line of flow to improve filling and prevent air entrapment.

An edge gate located below the parting line or molded surface.

Edge gate

A reinforced or protrusion on a mold part for strength or alignment during assembly or fastening.

Boss or rib