As a Die Casting specialist, Omnidex offers a lot more than what a typical factory can do for you. From die making to production engineering and QC, we can set everything up for you. There are a lot of things to consider in a Die Casting project, and here are what we think really matter to you.
We have been working with some of the best Die Casting factories in our region for many years. These factories can produce top quality products with highly accurate dimensions and tolerances. Also, you are not limited to the capacity of just one manufacturer, giving you more choice on materials and casting methods.
Your project is backed by our team of experienced in-house engineers. We use the very latest software to simulate molten metal flow during the Die Casting process so that we can highlight feed points and identify areas where improvements can be made. We are always ready to answer your questions concerning Die Casting and other manufacturing processes.
The die is the most important component in the process. Any problem in the die design may lead to inaccuracy or quality issues in the products. As an expert in Die Casting, we will provide you with the best die designs possible to ensure the success of your project.
Our production offers impeccable surface finishes through detailed final cleaning and specialized painting. We also guarantee clean sprue removal and keep waste to a minimum.
Issues such as flash, unfilled sections and hot tearing may occur in Die Casting. Our QC specialists will make sure the product is free of these problems, and the dimensions and properties are up to the agreed specification throughout the entire production run. Learn more about our QC process here.
The Die Casting process dates back to the early 19th century when tin and lead were poured into steel molds to produce type for printing. This process is characterized by forcing molten metal under high pressure into a mold cavity. Its potential was soon exploited and today it is used in virtually every industry.
There are 3 types of Die Casting methods:
This process involves heating metal in a separate furnace, then transferring the molten metal into the casting machine. It is used for metals with a higher melting point, such as aluminum, magnesium and copper.
Instead of using a separate furnace, metal is heated inside the casting machine. The injection mechanism involves a goose-neck machine placed inside a crucible, which can heat the metal to melting point and inject it into the die. It is typically used for metals with lower melting points such as zinc alloys. (Thanks to technology advancement, magnesium alloys can also be used.)
Multi-slide die casing uses tools with 4 perpendicular slides (in some cases up to 6 slides at angles other than 90°) to produce more complex and accurate castings. This process is used to produce small zinc alloy components at a rapid production rate (up to 4500 cycles per hour).
Die Casting Animation
It is best to use non-ferrous alloys such as aluminium, magnesium, zinc, brass and copper alloys for Die Casting.
Commonly used in handheld devices, electronic and telecommunication components and computer parts, aluminium die castings are not only lightweight, but also able to withstand the highest operating temperatures when compared to the other alloys.
Characteristics of aluminium alloys in Die Casting:
Aluminium alloy composition:
| Percentage of alloying material | A380 | A383 | A413 |
| Copper | 3.0 – 4.0 | 2.0 – 3.0 | 1.0 (maximum) |
| Iron | 1.3 (maximum) | 1.3 (maximum) | 2.0 (maximum) |
| Magnesium | 0.1 (maximum) | 0.1 (maximum) | 0.1 |
| Manganese | 0.5 (maximum) | 0.5 (maximum) | 0.35 |
| Silicon | 7.5 – 9.5 | 9.5 – 11.5 | 11.0 – 13.0 |
| Zinc | 3.0 (maximum) | 3.0 (maximum) | 5.0 |
| Nickel | 0.5 (maximum) | 0.3 (maximum) | 0.5 (maximum) |
| Tin | 0.35 (maximum) | 0.15 (maximum) | 0.15 |
| Other (in total) | 0.5 | 0.5 | 0.25 |
| Aluminum | Remainder | Remainder | Remainder |
Magnesium alloys are extremely light and durable but difficult to machine. It is used to make products where lightweight and durability is necessary, such as high-end electronics and camera components. Out of all the alloys used in die casting, it is the lightest and easiest to machine.
Characteristics of magnesium alloys in Die Casting:
Alloy AZ91D is a high-purity magnesium alloy widely used in die casting alloy. It offers an excellent combination of corrosion resistance, castability and mechanical properties. It has the following properties:
| Mechanical Property | Magnesium Az91D |
| Hardness | 63 Brinell |
| Elongation | 3% in 50mm |
| Tensile Strength | 230 MPa / 34psi |
| Yield Strength (0.2% offset) | 160 MPa / 23 psi |
| Shear Strength | 140 MPa / 20 psi |
| Impact Strength | 2 ft. Ib. |
The physical properties of Magnesium AZ91D are as follows:
| Physical Property | Magnesium AZ91D |
| Density | 1.81 g/cm²/ 0.66Ib/in² |
| Electrical Conductivity | 12.2% IACS |
| Thermal Conductivity | 72.3 W/m – K / 41.8 Btu-ft/h-ft °F |
| Coefficient of thermal expansion | 25.5 µm/m°K / 14 µin / in °F x 10^-6 |
| Melting Range | 470 °C – 595 °C (875 – 1105 °F) |
Zinc alloys are easiest to die cast and is a good low-cost alternative to fabricating or machining parts. It is commonly used in consumer electronics, computers, telecommunications and the automotive industry. Used in hot chamber machines, zinc alloy die castings have a smooth surface finish, allowing for plating and painting.
Characteristics of zinc alloys in Die Casting:
Zinc alloy compositions:
| Percentage of alloying material | Zamak 2 | Zamak 3 | Zamak 5 | Zamak 7 | ZA8 | ZA27 |
| Aluminum | 3.5 – 4.3 | 3.5 – 4.3 | 3.5 – 4.3 | 3.5 – 4.3 | 8.0 – 8.8 | 25.0 -28.0 |
| Copper | 2.5 – 3.0 | 2.5 maximum | 0.75 – 1.25 | 0.25 maximum | 0.8 – 1.3 | 2.0 – 2.5 |
| Magnesium | 0.02 – 0.05 | 0.02 – 0.05 | 0.03 – 0.08 | 0.005 – 0.02 | 0.015 – 0.03 | 0.01 – 0.02 |
| Iron | 0.1 maximum | 0.1 maximum | 0.1 maximum | 0.075 maximum | 0.075 maximum | 0.075 maximum |
| Lead | 0.005 maximum | 0.005 maximum | 0.005 maximum | 0.003 maximum | 0.006 maximum | 0.006 maximum |
| Cadmium | 0.004 maximum | 0.004 maximum | 0.004 maximum | 0.002 maximum | 0.006 maximum | 0.006 maximum |
| Tin | 0.003 maximum | 0.003 maximum | 0.003 maximum | 0.001 maximum | 0.003 maximum | 0.003 maximum |
| Zinc | Remainder | Remainder | Remainder | Remainder | Remainder | Remainder |
Brass is an alloy containing zinc and copper. It offers a variety of aesthetically pleasing finishes, both as cast and polished.
Characteristics of brass alloys in Die Casting:
Properties of brass:
| Property | Brass |
| Tensile Strength | 55 ( psi x 1000) |
| Yield Strength | 30 (psi x 1000 with 0.25 offset) |
| Shear Strength | 37 ( psi x 1000) |
| Fatigue Strength | 25 (psi x 1000) |
| Hardness | 91 Brinell |
| Impact Strength | 40 ft/lb |
Characteristics of copper alloys in Die Casting:
(please consult our sales department for more information)
Die Casting tolerances are based not only on the alloys used, but also the length, shape and location of each feature. There are several considerations when it comes to setting tolerances for a Die Casting part:
Tolerances looser than required will result in poor product quality and lifespan, whereas tolerances higher than required will result in higher scrap rate and product cost, so it is important to strike a balance between different factors and achieve tolerances that are as tight as necessary.
Therefore, it is important to highlight the functional requirements, as well as the critical dimensions and features on the part that are critical. From here we may choose the appropriate process and material to meet all these specifications and requirements.
Here is the Die Casting tolerance standards for your reference:
| Nominal dimension (mm) | Linear dimension Tolerances (mm)（ISO8062） | |||
| > | ≤ | CT4 | CT5 | CT6 |
| – | 10 | 0.26 | 0.36 | 0.52 |
| 10 | 16 | 0.28 | 0.38 | 0.54 |
| 16 | 25 | 0.3 | 0.42 | 0.58 |
| 25 | 40 | 0.32 | 0.46 | 0.64 |
| 40 | 63 | 0.36 | 0.5 | 0.7 |
| 63 | 100 | 0.4 | 0.56 | 0.78 |
| 100 | 160 | 0.44 | 0.62 | 0.88 |
| 160 | 250 | 0.5 | 0.7 | 1 |
| 250 | 400 | 0.56 | 0.78 | 1.1 |
| 400 | 630 | 0.64 | 0.9 | 1.2 |
| 630 | 1000 | 1 | 1.4 | |
| 1000 | 1600 | 1.6 |
There are many factors to consider when choosing the material for your project. Each alloy has different properties that may or may not be suitable for certain usage. Depending on your requirements, there may be several materials suitable for your project, or you may be able to get better results with another casting process. We highly recommend exploring all the options with us before making your decision.
Want to learn more about other casting processes? Check out other processes on our website.
Contact our Customer Service and let us know how we can help to catapult your next project to success.
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