Which process is better for cast parts, Sand or Die?

Die Casting and Sand Casting are two of the most commonly used manufacturing processes for metal products. These two types of production techniques have a few commonalities, but primarily have very different production process methods.

Furnace room for molten metal

Material options for these production methods

Sand cast parts have capabilities to utilized several categories of metal grade. The most used types include aluminum, grey iron, ductile iron, steel and magnesium. Die cast parts primarily use non-ferrous types of material: zinc, aluminum and magnesium alloy combinations.

How the cast part is created by each process

Sand and Die Casting both use a pre-built mold that forms one or multiple cavities. Next, the selected material is heated to a molten state and then injected to fill the cavity. After the cycle is complete, your cast part is now built.

A sand mold is built by packing sand into each half of the mold. The sand is packed around the pattern, which is a replica of the external shape of the casting. When the pattern is removed, the cavity that will form the casting remains. Complex internal shapes of the cast part, which cannot be formed by the pattern, are built by internal core inserts which are made of sand prior to the formation of the mold. Once the part has been formed, the sand mold is broken and the Sand cast part removed.

Die casting also requires a mold and tooling insert to produce the part, however these patterns can be more complex and be reused for hundreds of thousands of pieces. The die cast operation involves high pressure injection of molten metal metal into the mold. The molten metal is in direct contact with the mold during the entire die cast process. Standard die cast molds need to withstand high pressure and extreme heat forces during the operation. This is why Die Castings China prefers to used high strength, Dievar Steel for mold construction.

Required machinery for die casting, cost of producing molds from specialty steel create higher expenses than sand cast operations.

As a result of the higher cost, die cast services are mostly ideal for high volume production runs. Also, die casting is a good method of controlling any potential porosity issues.

Sand casting is cost effective for projects that require smaller quantities. Each process is able to produce high quality castings, however each process has its own pros and cons for production. At our die casting company, we specialize in high quantity production die cast parts that are made from aluminum or zinc alloy material types.


Sand Cast Die Cast
Dimensional Tolerances ±.010″ ±.030″ ±.001″ ±.015″
Relative Cost – High Part Quantity Low Lowest
Relative Cost – Low Part Quantity Lowest Highest
Weight Range Unlimited oz. – 75 lb
Minimum Wall Thickness 1/10″ 1/32″
RMS Finish 150 – 350 63 – 90
Draft Angle (Degrees) 1 – 5 1/2 – 2
Design Complexity/Detail Fair-good Good
Relative Ease of Design
Changes In Production
Best Poorest
 Alloys Most Ferrous / Non-ferrous Metals Al, Zinc, Mag Alloy combinations