Abstract: An induction furnace apparatus and method for reducing the magnetic field produced by the operation of the furnace. The induction furnace including a refractory vessel, an induction coil, and an outer shell having a layer of metallic and magnetically permeable material. The metallic and magnetically permeable material comprising a plurality of elements having a shape and size that is chosen to maximize the packing density of elements throughout the layer. The outer shell further including a top, base, and sidewall arranged about the refractory vessel such that the metallic and magnetically permeable material is formed between the refractory vessel and the outer shell. The invention provides a method for casting metallic and magnetically permeable material with or without a non-conductive matrix. The castings can be formed into inserts or incorporated into the top, base, and side wall of the outer shell.