What Drives CNC Mold Processing Costs

Mold work is different from standard CNC machining. The tolerances are tighter, the materials are harder, and the surface finish requirements are more demanding. When a client asks me for a mold processing price, I start with three questions: material, cavity complexity, and tolerance requirements.

Aluminum vs. steel. Aluminum molds are faster to machine and cost 30-50% less than hardened steel molds. They work well for prototype runs and low-volume production — typically under 10,000 cycles. Steel molds cost more upfront but last for hundreds of thousands of cycles. For production molds, H13, P20, and S7 tool steels are our most requested grades.

Cavity complexity. A simple two-plate mold with a single cavity is straightforward. Multi-cavity molds, molds with slides or lifters, and molds with thin-wall sections all require more machining time, specialized tooling, and additional programming. Complex molds can cost 2-3x a simple mold of the same size.

Tolerance impact. Standard mold tolerance for general applications is ±0.05mm. If the mold requires ±0.01mm on cavity dimensions — common for tight-tolerance injection molded parts — machining time can double. We discuss tolerance requirements upfront so there are no surprises in the quote.

AOOM's Mold Machining Approach

We use Mastercam for roughing and finishing toolpath optimization. On mold work, roughing efficiency matters — we remove 70-80% of material in the roughing phase, and the finishing pass determines the surface quality. We run high-speed machining strategies with constant tool engagement to maintain consistent tool load and avoid deflection.

For steel molds, we rough in the annealed state, heat treat to the required hardness (typically 48-52 HRC), and then finish-machine. This two-stage approach gives better dimensional stability. For aluminum molds, we single-machine in the T6 condition.

Price Ranges for Common Mold Work

Small aluminum injection molds typically run $800-$2,500. Medium steel stamping dies are $3,000-$8,000. Complex multi-slide molds with core pulls and tight tolerances start at $15,000. Every quote is custom — I don't send boilerplate numbers. I include material breakdown, machining time estimate, surface finish target, and expected delivery date.

Getting Started

For an accurate CNC mold processing quotation, send technical drawings with material specifications, surface finish requirements (Ra), and annual production volume. Our engineers review every inquiry and recommend the most cost-effective approach.

Send your CAD files to chen@aoomtech.com for a quote within 24 hours.