Die Casting

What is Die Casting?

Die casting is a manufacturing process in which molten metal is poured or forced into steel molds. The molds—also known as tools or dies—are created using steel and are specially designed for each project. This allows each component to be created with accuracy and repeatability. Aluminum, zinc, and magnesium are the most commonly used die casting alloys.

Zinc alloy and aluminum alloy die casting is a process of melting metal alloys and pouring them into a mold cavity to obtain parts with the desired shape and size. The molten metal is injected into the mold under pressure, which allows for greater control over the shape of the finished product. This process is often used in automotive, aerospace, medical, electrical and other industries where precision components are required. It offers many advantages such as low cost, high production rate, consistent product quality and superior surface finish. In addition, it can produce complex shapes that would otherwise be difficult or impossible to achieve with traditional manufacturing methods.

Advantage of Die Casting

Die casting can have significant advantages over other manufacturing processes, which often lead to major cost savings, not only in the part price itself but also in the overall cost of production. When you cast a part, you can create complex net shapes, including external threads and complex internal features with minimal draft angles—minimizing secondary operations. You can also combine multiple parts into a single part, eliminating assembly operations and lowering labor costs, with the added benefits of simplified stock control and greater component consistency.

Other benefits include:

Variable wall thicknesses

Tighter tolerances

Fewer steps from raw material to finished part

Fast production cycle times

Reduction in material scrap

Long tool life, especially for zinc and magnesium

Terminology of Die Casting Mold

Draft– A certain degree of angle that allows die casting product to fall off from mold tool easily.

Parting Line– a small line left between the fitting area of mold core and cavity. It looks like a flash line.

Gate– The material running channel that attached on die casting product

Mold Core– The outstanding plate that mates with mold cavity to consist the die casting features.

Mold Cavity– A recessed plate that allows molten material to fill in and solidify.

Slide— A mechanical device to obtain some special features that can’t be directly produced by mold core and cavity side.

Injection— A filling process by high pressure that forces the molten material into mold tool.

Ejection Marks— Marks left by the ejection pins on the surface of die casting product. This mark caused by the small space between moveable pins and ejection plate.

Ejection Pins— The moveable pins inside a mold tool that used to push off die casting product from mold tool.

Runner— The material flowing channel in the die casting mold that starts from sprue and ends by die casting product.

Overflow – An additional reservoir connects with die casting product that used to avoid or reduce injection bubble and other die casting defects.

Sprue— A small hole in the die casting mold. It’s also an entrance of raw material to die casting runner and parts

Vent— A small space that recessed from mold core and cavity so that air or gases can evacuate out from the mold when material filling process.

Clamping Plate–a mold plate inside a mold tool that used to mount mold tool on die casting machine.

DFM and Refining:


die casting 2.pngDraft is the a certain angle of the tooling core or parts to be easily released when die casting production process. All die cast surfaces that are parallel to the opening direction of the die require draft for the proper ejection of the casting from the die. Otherwise there must be a potential manufacturing risk for the die mold.

Fillet is round juncture of two surfaces that would have otherwise met at a sharp corner or edge. When die casting part design, experienced product designer must put some fillets on the optimized parts so as to remove undesirable edges and corners, as well for stress concentration consideration.


Pillar is designed to support some stand-offs surface or to assemble other parts with screws. Based on our experience, for maximum integrity and strength of the die casting reason, The thickness of pillar must be equal or exceed the universal wall thickness. Otherwise the pillar might be easily cracked.


Rib is designed to strength walls, surface, or other functional features, so that the target part will be strong enough for any work condition. For die casting manufacturing consideration, we sincerely comment our client can make the thickness ribs at 50%~80% of universal wall thickness. So as to eliminate or reduce shrinkage of the parts during the casting process.


Holes and windows We would specially advise adding proper draft on holes and window feature, because when die casting manufacturing, the perimeters of these features will grip to the die steel during solidification.

With over 20 year of die casting molding experience, we consider every mold details so that there will be no problem for mass production. During the process, our sophisticated engineers will work very closely and provide DFM report, Moldflow analysis according to the 3D/2D Mould Drawing from client. 

(We are willing to sign your NDA (Non Disclosure Agreement) and thus help protect your IP and protect your product design.)

die casting.png

We will design a best workable die casting process based on analysis of product material, structure, tolerance, and other special requirement.

Define product layout, cavity, parting line, gate, runner, ejection pins, overflows.

Check out if all of sliders/lifters are correctly located. If the movement of slider will go smoothly.

Check out if the ejection mark and parting lines are designed properly(minimum and reasonable)

Check out if there is any interference when mold is working.

If the shrinkage rate is correctly design

Check out mold cavity, slider number, and other mold accessories


  • Professional and comprehensive Design for manufacturability (DFM) report
    Minimum die casting tolerance of ±0.10mm.
  • Minimum die casting thickness of 1.2mm

  • Great economic benefits

    Based on our die-casting skills and vast experience, Metal Driven (Changhong Precision)’s engineering team not only has the ability to reduce the amount of materials removed, but also, helps customers to save material and reduce costs by optimizing the die casting processes, without sacrificing quality.

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Contact: Linmer

Phone: 0086-18617135287


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