In mold work, the first thing to get straight is classification, because it drives everything downstream—structure, material selection, and price. Stamping dies, injection molds, die-casting molds, and forging dies each carry different design logic and cost structures. Take injection molds: a two-plate mold is the workhorse for simple parts, while a three-plate mold adds a runner plate for multi-point gating and automatic degating. On the shop floor, the cavity layout, slider and lifter count, and ejection scheme are decided early, and every one of these adds machining hours and steel cost. A mold with two sliders and one lifter can easily run 30–50% higher than a simple two-plate tool of the same size.
Structure follows function, but quotation follows structure. A mold quote is not a single number—it breaks down into cavity steel, standard parts (leader pins, bushings, springs, ejector pins), hot runner system if used, machining hours for CNC, EDM, wire cut, and fitting, plus trial run and surface treatment. A typical small-to-medium injection mold might use P20 or 718H for the cavity and core, with a 1×2 or 1×4 layout; a hot runner system alone can add several thousand dollars. Die-casting molds need H13 or SKD61 with heat treatment, and the thermal fatigue allowance pushes both material and lead time up. When quoting, experienced engineers separate steel cost, machining cost, and risk buffer—never lump them into one figure, or you lose control when the customer changes the part design.
What separates a good quote from a bad one is asking the right questions before pricing: part geometry, annual volume, tolerance requirements, surface finish, and expected mold life. A 500,000-shot production mold and a 50,000-shot prototype tool should never share a price sheet. Keep your steel certificates, machining records, and trial reports organized—they back up your quote when the customer pushes back. For more mold sourcing and supplier information, visit MoldSo at www.moldso.com.