Gating of castings is a very “metal caster-specific” subject among all casting alloys and all mold cavity-making processes, and personal opinions abound. Since steel castings, across all of its alloys and processes, are especially difficult to produce, manufacturing engineering of gating is a very “near and dear” skill set. So, gating is a special arrow in a steel casting producer’s quiver that enables a difficult design to be produced to specifications.
Regardless of personal preferences for specific gating geometry, runner and in-gate sizing and ratios, pressurized systems or unpressurized, and filters/no filters, there are 5 fundamentals of physics that are involved in gating effectiveness that transcend those more personal preferences. The 5 fundamentals also apply equally well among all the steel casting alloys and among all the mold cavity-making processes, including the investment process.