A few different die casting metal options are available when making metal parts. If you are researching using die casting for a product in your industry, you may well be wondering which of these metals would be best for you. Read on to learn the differences metals make in die casting and which are the best choices for various industries.
The alloys you will typically choose from when it comes to die casting are aluminum, magnesium and zinc. There are other metal alloys you can use for die casting as well, like copper, brass, tin and lead, though these alloys are much less-common, specialty materials in the die casting industry. Since we’re working with alloys, or elements in a mixture, you will find metal die cast parts that incorporate several of these metals. Each alloy has different properties and different advantages and disadvantages that make them appropriate for different kinds of applications.
If you make parts for vehicles like trucks or RVs, what kind of die cast metal should you be using? Should you use the same metal for truck parts as you do small engines? Although mostly-aluminum parts are a little more expensive, aluminum and aluminum-zinc alloys are usually the top choice when it comes to automobile, truck and other vehicle parts and gears.
This is because aluminum alloys are very corrosion-resistant, have a good strength/stiffness weight ratio and are lightweight, which can mean better gas mileage for heavy trucks and RVs. Aluminum alloys are also relatively easy to cast and have high electrical and thermal conductivity, which makes them a popular choice for casting parts in the lighting, electrical and computing fields as well.
The metal you use for your medical equipment will depend on the type of equipment you are making, but you will often find medical equipment die cast parts made of zinc or magnesium as well as aluminum. Zinc castings are popular when your item is a patient-facing device that needs an attractive painted or plated finish, since zinc provides a very smooth surface to work on and can be plated easier than aluminum die castings. You can also easily make very thin-walled parts with zinc, which is critical when weight is an important factor in a specific application.
Zinc has a low melting point, which provides for longer mold life than aluminum die casting offers. Like aluminum, zinc has great corrosion resistance and high thermal conductivity. It’s quite durable, strong and hard and offers a great deal of dimensional stability.
Magnesium is a great choice for die casting when you need very light parts. Magnesium is extremely lightweight, with a high strength to weight ratio, low density, good corrosion resistance and good electrical and thermal conductivity. On the other hand, it’s more difficult to die cast due to its handling requirements, and it’s considered a “specialty” alloy in the die casting industry. There are not many die casters pouring magnesium alloys so supply constraints may be an issue if you have high volume parts.
If you do some research, you will find many people who explain that gun parts are made of “gunmetal,” which is not very helpful. You may hear it referred to as “red brass,” which doesn’t tell you much either. In fact, gunmetal is an alloy that includes copper, zinc and tin. This choice is a popular one because it’s highly temperature-resistant, extremely hard and exceptionally resistant to corrosion.
Most guns are made mostly of steel, as steel has even more desirable properties for guns, although parts for certain guns are still often made from aluminum, zinc alloys or even special plastics today. Aluminum is used in guns where high strength is not required like trigger guards.
As you can see, different applications are better suited for different metals, and the metal that should predominate in your die cast parts is very specific to your product and your industry.
If the ability to withstand high temperatures is your highest priority, you will want a mostly aluminum alloy in your die cast part, although it is crucial to note that aluminum can only be die cast with a cold chamber machine. Other alloys, like zinc or magnesium, can work with hot or cold chamber machines. This distinction is important in the selection of a die cast vendor, as you’ll need to consider their available equipment.
If a lightweight part is your highest priority, you will usually want to go with magnesium, which is extremely light. However, a problem with magnesium is that there is a limited supply base of die casters in the U.S. at this time.
If ease of casting, economy and a great-looking final product are your top priorities, you may want to look more into zinc alloys, which cast very simply, still have good strength, hardness and dimensional stability and are quite easy on your dies, giving them a longer life than aluminum alloys have.
If corrosion resistance is your number-one requirement — for example, your parts are used in the food service industry — consider stainless steel and nickel alloys which are a specialty process with limited capacity in the US. For high electrical and thermal conductivity, strength and wear-resistance, consider brass which is another special alloy.
If you’re still not entirely sure which metal is right for your die
cast parts, don’t worry. We understand that you’re not an expert in die casting or metal machining, and you don’t have to be. Premier Die Casting is here to help. For over 70 years, Premier Die Casting has provided CNC machining, die casting, metal finishing and assembly services. We specialize in aluminum die casting, as we find that aluminum combines virtually all the best properties of the most popular alloys.
We’re happy to help you figure out which metals and which machining processes you need for your particular projects. We use state-of-the-art machines and technology to make sure you always get beautiful, reliable parts that last. Contact us today to tell us about your industry and needs so that we can come up with the right plan for your project. We work with medical companies, telecommunications, lighting and more — and we’ll be happy to come up with a solution for your industry.
