Home Industry Aluminum Mold Vs. Steel Mold: Which Is Better?

Aluminum Mold Vs. Steel Mold: Which Is Better?

by Whitney

Various metallurgical techniques use molds to create the required shapes. Some standard methods that use molds or dies are injection molding, blow molding, compression molding, etc. Hence, mold occupies an indispensable position in the metal-forming world.

Material shaping molds are prepared from materials with exceptionally high melting points and yield strengths to hold the hot metal or plastic without deforming. The common materials used to create dies are steel and aluminum.

Steel is an iron alloy infused with carbon to increase its material strength. At the same time, aluminum belongs to the IIIa group of the periodic table and is the most abundant metal in Earth’s crust. But which metal will work best for creating molds? Is an aluminum mold better than a steel one?

Comparing Aluminum and Steel Molds

Both materials are used in commercial metalworking plants. However, each of them has its ideal use case. Below is an end-to-end comparison of both materials to help you pick the most optimal one.

Compatibility With Multiple Resins

The primary benefit of using steel molds is their suitability with various resins. Structurally complicated resins (the ones infused with fibers, glass, or other additives) are molded perfectly in steel molds without affecting their composition.

In comparison, aluminum molds are soft and are more likely to attain scratches if the resins contain additives. Therefore, when opting for material for constructing molds, ensure that the mold is compatible with the working material. Scratched molds, in turn, affect the external appearance of the component.


Steel’s melting point is 2200 to 2500 degrees Celsius, while aluminum’s is 660 degrees Celsius. So steel molds are more resilient to higher temperatures than aluminum molds. The more increased endurance of steel makes it long-lasting than aluminum.

Ideal For Mass Production

Steel molds last longer and can produce many pieces before giving up their strengths. The long service time of the mold outbalances its initial upfront. It is important to note that crude steel is more inexpensive than aluminum; however, more machining effort is required to create the mold shape since it is hard. In comparison, aluminum is soft, so the molds are more inexpensive than steel ones.

Detail Sensitivity

Not all components are simple-structured, so the mold must maintain the design’s details to the maximum. Steel molds produce sharper and more precise feature details than aluminum molds; therefore, they are best for creating complicated geometries.

In comparison, aluminum is soft, so pointed or complexly shaped molds deform much more quicker. Resultantly, the final piece doesn’t have the highest precision as well.

Per-Component Costs

The per-part expense significantly depends upon the magnitude of production. The cost of a single element is less in larger productions as compared to smaller batches. If the production quantity is less, it is better to pick aluminum molds as they can help the per-part costs. However, if the production quantity is massive, like millions of pieces, steel molds make the ideal pick.

Cooling Time

Aluminum has better heat conductivity than steel molds. Hence, the cooling time is reduced, lessening the preparation time. In contrast, steel has less heat conductance, so the cooling process is seven times slower.


Both aluminum and steel make ideal choices for creating dies and molds. However, each has its highs and lows. Since molds greatly dictate the final price of the manufactured component picking the best material for molds is viral.

Aluminum molds work best with smaller productions, shorter deadlines, and a lower budget. In comparison, steel molds are perfect for mass production and lenient deadlines. However, the initial upfront costs are significant.

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