Die Casting Mold Making

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What is Die Casting Mold?

Die Casting moldDie casting mold is a manufacturing tool that used to produce metal casting parts(could be aluminum, zinc, and magnesium alloy products) on die casting machine. There are mainly two different type of die casting machines as hot chamber machine and cold chamber machine. The main difference is that in hot chamber casting machines is facilitated with interior material container with the molten metal, but the cold chamber machine is equipped with separated material furnace.


Any type of die casting molds consist of two plates with cavity or core(it’s also called A side and B side), which enables the cast part to be removed from mold tool. Normally the A side plate is assembled on a fixed plate on die casting machine, while the other plate is mounted onto a movable plate of a casting machine.


During a die casting process, the molten metal is first filled into the cavity of the mold tool at a low speed or high speed( it depends on which type of die casting machine that you need to use), it takes few seconds to solidify and become the desired parts as needed. Finally the casting parts will be ejected out from mold tool. This is the whole die casting process.

Common Terminology of Die Casting Mold

  • The Die Casting Mold-StructureDraft – It’s also called draft angle that is designed to enable the desired casting parts to be easier fall off from mold cavity when ejection process.
  • Gate – An extra flowing material that lead through injection runner and desired parts. After injection process is finished, the gate would be trimmed from parts by manual or machine.
  • Mould Core– The extrusion and recessed features on the mold that forms a desired casting part.
  • Overflow – A small additional reservoir between product and runner system that used to avoid injection bubble and other die casting defects.
  • Parting Line– A small and light line left on casting parts, which happens the fitting area of mold core and cavity.( it looks like a flash line)
  • Ejector— A mechanism device that equipped on casting mold, used to push the die casting part fall off.
  • Clamping Plate –the mold basement that used to clamp mold onto casting machine.


Seven Typical Process of Die Casting Making



die casting moldStep 1: Product DFM & Mold Design 

A systematic product DFM is the first step to make a die casting mold. Whatever how perfect your product design might be, however there is always a necessary to perform a DFM analysis for die casting manufacturing. According to our experience, most of time, we helped clients to refine draft angle, adjust thickness of wall, change features for part removal from mold.

After DFM analysis is completed, we will start mold design immediately. Our sophisticated designers utilize Pro/E, UG, Solidworks, Moldflow, Auto CAD for mould design as common, but our dedicated designers would strive for a best solution to improve product quality and efficiency while not increasing manufacturing cost or reducing cost.

During the mold design process, we will define mold layout, gate type, parting line, overflows, ejection system, and mold base. All of these details would be documented with 3D and 2D drawing.

Step 2: Mold Steel and Other Accessories Purchase

We will out-source mold steel and some other accessories locally once mold design is finalized. And get them full inspected for both dimensional and material properties, which enables to have correct material.

Step 3: CNC Machining 

Once we got mold steel, firstly we will drill locating holes and CNC-machine mold core and cavity roughly, which means to remove most of extra material and remains about 0.2mm for EDM or CNC final machining. Normally this process takes about few hours.

Step 4: Heat Treatment

Most of time, we need to get our mold core and cavity steel tempered with HRC 38~45 degree. Especially for aluminum die casting mold, which has to withstand high temperature while the mold works.

Step 5: WireCutting/EDM/Milling/Drilling/

While the CNC rough machining and heat treatment are processing, we are simultaneously doing wire cutting to obtain individual sliders, holes, square lifters.

EDM and milling process are also very common way to produce particular mold features, like windows, holes, groove, pillar, etc. This process take much longer time as it works very slow and precision,

Step 6: Mold Fitting, Assembly, and Trial

When every mold component is ready, we will need to get all of components fitted and assembled together.

If mold assembly is finished, it’s time to get the mold tested to validate if there is any mistake or imperfection.

Step 7: Refine, polish, and Texture

When first molded sample(T0) is ready, we need to review and find out if there is anything to improve. If needed, we will record and follow up the imperfections for next around of mold trail.

If the final casting product meets our specification, it’s time to polish and texture the mold. Then the whole process is signed off.

The Flowchat of Die Casting Making

die casting mold-making-process

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