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Aluminum has a density of about 2.70 g/cm³. That answer takes one line. Using it to predict the weight and cost of a die-cast part is where things become less simple.
A buyer may multiply the CAD volume by 2.70 and expect the quotation to follow. Then the first samples arrive heavier than expected, the material estimate changes, or the die caster explains that the shot weight is much higher than the finished-part weight. None of this means the density value is wrong. It means density is only one part of the calculation.
At Huayinsheng, we use density as a starting point—not as a shortcut. The alloy, net part volume, runner and overflow system, machining allowance, inserts, surface finish and production yield all affect the number that finally matters: the cost of a conforming finished part.
The commonly quoted density of aluminum is approximately 2.70 g/cm³ at room temperature. The same value can be written as:
This is why aluminum is attractive for housings, brackets, covers and structural components where weight matters. It is roughly one-third the density of steel and substantially lighter than zinc alloys.
However, a die-casting buyer is rarely purchasing pure aluminum. The actual material is an alloy containing silicon, copper, iron and other elements. Those additions change castability, strength, machining behavior—and density.
ADC12 is the aluminum die-casting alloy Huayinsheng uses most often. Its typical density is approximately 2.74 g/cm³. The exact value can vary slightly with the applicable material specification and actual chemical composition, so certified material data should be used when a project requires a controlled engineering calculation.
| Material | Typical density | Practical meaning |
|---|---|---|
| Pure aluminum | About 2.70 g/cm³ | Useful as a general reference, but not the best value for every casting alloy |
| ADC12 | About 2.74 g/cm³ | A practical starting value for the aluminum alloy we commonly die cast |
| Zamak 3 / Zamak 5 | About 6.6–6.7 g/cm³ | Much heavier, but often excellent for thin walls, fine detail and dimensional stability |
These are typical engineering values for early comparison, not substitutes for a project-specific material certificate.
Weight (g) = Volume (cm³) × Density (g/cm³)
For an ADC12 part: Weight (g) ≈ CAD volume (cm³) × 2.74
Suppose a finished component has a net CAD volume of 125 cm³:
A five-gram difference may look unimportant. Across hundreds of thousands of parts, it is no longer a rounding error. But even 342.5 g is still only the theoretical net casting weight. It is not the amount of metal the die-casting machine must inject for every shot.
Molten metal does not travel directly into the product and stop. A practical die-casting system also needs a biscuit, runners, gates and overflows. Those features carry metal into the cavity, control filling and collect material at locations selected by the tooling engineer.
After casting, this additional metal is trimmed away and normally returned to a controlled recycling stream. It may not remain in the finished component, but it still affects machine selection, melt handling, cycle economics and the amount of metal circulating through production.
Huayinsheng’s view: A low net part weight does not automatically mean a low-cost casting. A difficult flow path, excessive overflows, thick machining stock or an inefficient cavity layout can consume the apparent material advantage.
Using 2.70 g/cm³ for every aluminum alloy is convenient, but it creates avoidable error. Use the density of the specified alloy for serious estimates.
The CAD model normally shows the saleable part, not the full shot. Tool design determines how much additional metal is required to fill the part consistently.
A finished component may be lighter after drilling, milling or thread machining. Yet the casting needed machining allowance, fixtures, cutting time, tool life and inspection. Lower finished weight does not mean lower total cost.
Steel pins, threaded inserts, bearings, seals and fasteners are not included when the aluminum CAD body is calculated alone. They must be counted when shipping weight or assembled-product weight matters.
Powder coating, painting, plating and other finishes add a small amount of material. The weight difference may be minor, but masking, appearance control and finishing inspection can have a meaningful cost impact. Huayinsheng manages these processes through qualified long-term finishing partners and performs incoming and final quality verification.
Metal can be recycled, but rejected castings still consume melting capacity, machine time, trimming, inspection and energy. Stable tooling and process control matter more than a perfect spreadsheet estimate.
Projected area, flow distance, wall thickness and required clamping force influence machine selection. Huayinsheng operates die-casting machines from 88T to 400T. We do not select a machine from part weight alone.
For the same solid volume, a zinc alloy part can weigh well over twice as much as an aluminum part. That makes aluminum the obvious candidate when low mass is the priority. But material density does not decide the full business case.
Zamak 3 and Zamak 5 can offer excellent fluidity, thin-wall capability, fine detail, dimensional stability and long die life. Huayinsheng has produced zinc die-cast sections at 1.0 mm, with local areas reaching 0.8 mm, subject to geometry and flow evaluation. For ADC12 aluminum parts, sections around 1.5 mm may be feasible depending on part size, flow distance and tooling design.
The right question is therefore not “Which material is lighter?” It is:
Which material can meet the functional, dimensional, appearance and production-volume requirements at the lowest total delivered cost?
Yes, but the comparison must use the same condition. Check whether the sample includes machining, inserts, coating, oil, residual burrs or assembled hardware. A small difference between calculated and measured weight does not automatically indicate a material problem.
A useful review follows this order:
For quality control, weight can be a fast process signal, but it is not a substitute for dimensional inspection, material verification, X-ray analysis or leak testing when those controls are required.
A useful quotation begins with more than a density value. Send us:
Our team reviews the drawing, estimates net weight, evaluates manufacturability and considers the full route from tooling through casting, CNC machining, managed surface finishing, inspection, assembly and packaging.
The commonly quoted value is approximately 2.70 g/cm³. Individual aluminum alloys may differ, so use the specified alloy value for engineering calculations.
A typical early-estimate value is approximately 2.74 g/cm³. Project documentation and the relevant material specification should govern controlled calculations.
Yes. Aluminum is much less dense than Zamak zinc alloys. However, weight alone does not determine tooling life, wall thickness, surface quality or total part cost.
Yes. Send the 3D model, alloy requirement and annual quantity. We can estimate theoretical net weight and then evaluate the additional production factors required for a practical die-casting quotation.
Send Huayinsheng your drawing, alloy, annual quantity and finishing requirements. We will review the weight, manufacturability and complete production route before quoting.
