The traditional die-casting process mainly consists of four steps, or is called high-pressure die-casting. These four steps include mold preparation, filling, injection and shakeout, and are the basis for various modified die casting processes. During the preparation process, lubricant needs to be sprayed into the mold cavity. In addition to helping to control the temperature of the mold, lubricant can also help in the demoulding of the casting. The mold can then be closed and the molten metal is injected into the mold using high pressure, ranging from approximately 10 to 175 MPa. Once the molten metal is filled, the pressure is maintained until the casting solidifies. Then the push rod will push out all the castings. Since there may be multiple cavities in a mold, multiple castings may be produced in each casting process. The sand shakeout process requires separation of residues, including mold openings, runners, gates and flash edges. This process is usually accomplished by extruding the casting through a special trimming die. Other methods of sanding include sawing and sanding. If the gate is fragile, you can directly smash the casting, which can save manpower. Excess mold openings can be reused after melting. Typical yield is approximately 67%.

High-pressure injection results in filling the mold very quickly, so that the entire mold is filled with molten metal before any part solidifies. In this way, surface discontinuities can be avoided even in thin-walled sections that are difficult to fill. However, this can also lead to air entrapment, since it is difficult for air to escape when filling the mold quickly. This problem can be reduced by placing vents on the parting line, but even very precise processes can leave air holes in the center of the casting. Most die castings can use secondary processing to complete some structures that cannot be completed by casting, such as drilling and polishing.

After the shakeout is completed, defects can be inspected. The most common defects include stagnation (not enough pouring) and cold scars. These defects may be caused by insufficient temperature of the mold or molten metal, impurities in the metal, too few vents, too much lubricant, etc. Other defects include blowholes, shrinkage cavities, heat cracks, and flow marks. Flow marks are marks left on the surface of a casting caused by gate defects, sharp corners, or excess lubricant.

Water-based lubricants, known as emulsions, are the most commonly used type of lubricant due to health, environmental and safety concerns. Unlike solvent-based lubricants, if the minerals in the water are removed using appropriate processes, they will not leave by-products in the casting. If water is not treated properly, minerals in the water can cause surface defects and discontinuities in castings. There are four main types of water-based lubricants: water-oil, oil-water, semi-synthetic, and synthetic. A water-oil lubricant is best because when using a lubricant, the water will cool the surface of the mold through evaporation while depositing oil, which can aid demoulding. Typically, the ratio of this type of lubricant is 30 parts water to 1 part oil. In extreme cases, this ratio can reach 100:1.

Oils that can be used as lubricants include heavy oils, animal fats, vegetable fats and synthetic oils. Heavy residual oil is more viscous at room temperature, but at the high temperatures of the die casting process it turns into a thin film. Adding other substances to the lubricant can control the viscosity and thermal properties of the emulsion. These materials include graphite, aluminum and mica. Other chemical additives prevent dust and oxidation. Emulsifiers can be added to water-based lubricants so that oil-based lubricants can be added to the water, including soap, alcohol, and ethylene oxide.

For a long time, commonly used solvent-based lubricants include diesel and gasoline. They facilitate casting ejection, however small explosions occur during each die-casting process, which results in the accumulation of carbon on the mold cavity walls. Solvent-based lubricants are more uniform than water-based lubricants.