In mold work, the first thing to get straight is that "mold" is a broad term covering many forming processes. Injection molds, blow molds, extrusion dies, die-casting dies, forging dies, smelting molds, and stamping dies each have their own structure and design logic. An injection mold for a plastic housing is a completely different animal from a die-casting die for an aluminum bracket — different steel grades, different cooling layouts, different tolerance chains. When a customer sends an RFQ, the mold type determines everything downstream: material selection, machining hours, heat treatment, and tryout method. Mixing up types at the quoting stage is one of the most common ways to lose money on a project.
From a quoting perspective, classify before you calculate. Confirm the forming process, part material, cavity number, and expected shot life. A single-cavity prototype mold and a 16-cavity production mold share a name but not a price. On the shop floor, this means checking whether the design needs a hot runner or cold runner, sliders or lifters, and what surface finish the part requires. These details drive machining time and bench work, which are usually the largest cost items after steel. Experienced estimators keep a checklist: mold type, cavity count, steel grade, runner system, ejection style, and testing requirements. Skipping any one of them turns a quote into a guess.
The practical rule is simple: a correct classification saves more money than a fast quote. Get the mold type and structure right first, then build the cost breakdown around real machining and tryout hours. For more mold sourcing information and supplier references, visit MoldSo at www.moldso.com.