High Strength Aluminum: 2024 & 7075

2024 and 7075 are high-strength aluminum alloys that are commonly used in various applications, especially in aerospace, automotive, and structural industries.

2024 Aluminum

  1. Composition: 2024 aluminum is composed of aluminum (90.7%), copper (4.5%), and small amounts of other elements like magnesium (1.5%) and manganese (0.6%).
  2. Strength: It is known for its excellent strength-to-weight ratio, making it suitable for structural applications.
  3. Machinability: 2024 aluminum has good machinability and responds well to various machining operations.
  4. Corrosion Resistance: While it is not as corrosion-resistant as some other aluminum alloys, it can be protected through surface treatments such as anodizing.
  5. Applications: 2024 aluminum is commonly used in aircraft structures, where its high strength and lightweight properties are crucial. It’s also used in various aerospace and transportation components.

7075 Aluminum

  1. Composition: 7075 aluminum is composed mainly of aluminum (87.1%), zinc (5.3%), copper (2.1%), and small amounts of other elements like magnesium and chromium.
  2. Strength: It is one of the highest-strength aluminum alloys available, with excellent tensile strength and toughness.
  3. Machinability: While it can be machined, it is less machinable compared to 2024 due to its higher hardness.
  4. Corrosion Resistance: 7075 has good corrosion resistance, but it is not as corrosion-resistant as some other aluminum alloys. Anodizing can be used to enhance its corrosion resistance.
  5. Applications: 7075 aluminum is used in applications where high strength is required. It’s also used in the manufacturing of high-stress components in the automotive and aerospace industries.

Both 2024 and 7075 aluminum are valued for their high strength. They are used in applications where lightweight and strong materials are essential. The choice between them depends on specific application requirements, machining considerations, and cost constraints.

What is the difference between Aluminum Association, American Standard and Sharp Corner?

It’s one of those pieces of information that we all seem to misplace…what really IS the difference between Aluminum Association, American Standard and Sharp Corner products?

First, let’s name that shape! The base, or depth, is often noted as the first dimension of the shape. The thickness, or web, is the thickness of the base/depth. Lastly, the legs or flanges are the uprights of the channel.

Each of the different types, Aluminum Association (AA), American Standard (AS) and Sharp Corner (often called Architectural) have a different combination of leg and interior corner types.

Aluminum Association (AA) has curved (radius) interior corners and straight legs with flat ends.

Need help remembering? We like to make a connection between letters AA in Aluminum Association, and the flat ends of the legs.

American Standard (AS), on the other hand does not have ANY flat or sharp corner in its interior or legs. The legs taper from thick to thin and have rounded ends. You can almost see the shape of an “S” between the rounded legs and the radius interior corner.

Everything about “Sharp Corner” is what it sounds like! 90 degree interior corners and straight legs with flat ends make everything angular. Sharp Corner, or Architectural also only comes in aluminum alloy 6063.

How it’s Made: Aluminum

Aluminum, whether or not you know, is present in our daily lives in some fashion. But how did it get that way?

Let’s step back to look at how aluminum is made.

The first step in aluminum production is mining. Mining takes place in Bauxite-rich regions of the world such as the Caribbean, Australia and Africa. Bauxite is a naturally occurring ore that contains aluminum silicates that took millions of years to create from the natural chemical weathering of rocks.

After mining comes refining. Bauxite alone does not create aluminum, it’s the process of grinding the Bauxite and adding it to a mix of caustic soda and lime to which high heat is applied. After this intense process of heat and pressure occurs, aluminum oxide is created and precipitated out of the mix. It is washed and heated again. Now the mix looks like a white powder and is called ‘Alumina’. Alumina is also known as ‘aluminum oxide’.

Alumina is then smelted, which is an electrolytic reduction process. Electric current is passed through the bath of dissolved alumina and the aluminum metal is created and separates from the original chemical solution.

We aren’t done yet! After the aluminum is created it goes back into a furnace and is mixed with other metals or elements according to a precise scientific recipe in order to create a molten metal that is chemically suitable for certain applications. Purification then occurs and the molten metal is cast into ingots or molds and cools, awaiting its final processing.

Lastly, the ingot or cast material is either rolled, forged, drawn or extruded into its final form: sheet, plate, bar, tube or custom extrusion.

Bar stock can end up as the screws you buy from a hardware store and sheet products could be formed into a filing cabinet you use for important documents.

Next time you use or see something in your daily life that is aluminum- remember the long process it took to get that way and all the people and processing that happened along the way.

Tempering Designations for Aluminum

Aluminum is naturally a soft, low-density metal – too soft to be used for any structural applications in its pure form. Yet we see aluminum used regularly in high stress applications: construction, aircraft, even space shuttles. So how does such a ductile metal become so strong?
The first step is creating an aluminum alloy. Adding alloying elements such as copper, silicon and magnesium modify the mechanical properties of aluminum to produce a stronger metal. Further processing can then be done to add even more strength and durability to aluminum. One of the most popular methods of doing this is through tempering.

What is Tempering?
With controlled application of heat, metal is raised to nearly its critical temperature – a temperature just short of melting, high enough to alter a metal’s mechanical properties and relieve its internal stresses. The heat treatment is used to increase the hardness and ductility, while it decreases brittleness to prevent cracking and breakage. There are several different methods to produce the desired result, but the overall process is known as tempering.

What is an Aluminum Tempering Designation?
Once the tempering process is complete, the metal’s hardness is referred to as its temper. Its tempering designation identifies exactly what kind of heat treatment the metal has undergone. This is helpful in identifying the strength of a particular type of aluminum, and mechanical applications it is best suited for. Two pieces of aluminum alloy may have the same chemical composition, but if they have different tempering designations, their uses can be quite different.

What are the Tempering Designations?
The tempering designation is a two-character code attached after the aluminum alloy designation. The first character is a letter which identifies the type of tempering treatment used on the aluminum:

F: As fabricated. These are known as ‘semi-finished’ products, and often used in creating other finished tempers.
H: Strain hardened, used for wrought aluminum types which are non-heat treatable.
O: Annealed, which results in the lowest strength of tempered aluminum that has greater workability.
T: Thermally treated. These types of aluminum are heat-treated, quenched, and aged.

The second character of the tempering designation is a digit from 1-10, which helps to specify exactly how the tempering method was done. For instance, all T-series aluminum are thermally treated, but a naturally aged aluminum will have a different digit assignment than an artificially aged one. This level of detail helps to easily classify the type of aluminum and how it might best be used.

The T-series tempering designation is the most commonly used for aluminum, which can serve as an example showing the different tempering methods:

T1: Naturally aged after cooling from high temperatures during the forming process
T2: Cooled after a high-temperature forming process, cold worked, then naturally aged
T3: Solution heat-treated, cold worked, then naturally aged
T4: Naturally aged after a solution heat treatment
T5: Artificially aged after cooling from high temperatures during the forming process
T6: Artificially aged after a solution heat treatment
T7: Solution heat-treated, then overaged
T8: Solution heat-treated, cold worked, then artificially aged
T9: Solution heat-treated, artificially aged, then cold worked
T10: Cooled after a high-temperature forming process, cold worked, then naturally aged

Once familiar with these designations, it’s possible to quickly identify an aluminum alloy’s composition, tempering, and processing. Rather than looking up every type and grade, the tempering designation helps a buyer narrow their search for the strongest and hardest aluminum they need for the intended application.

How Diamond Plate is Made

One of the best ways to ensure worker safety in industrial environments is by preventing falls. Proper footwear with non-skid soles is a must, but there will still be a risk of slipping on stairs and walkways. A textured surface in these areas will produce more friction while walking, providing better traction to prevent worker falls. One of the most common methods to improve slip resistance is the use of diamond plate in these high-traffic areas.

What is Diamond Plate?
Diamond plate goes by many names, including tread plate, checker plate, and deck plate. Whatever the name, it all refers to the same thing: metal flooring with a raised diamond pattern on one side. It can be made of various types of materials from metals to plastic, but is most often produced from aluminum, hot rolled steel, and stainless steel.
Because aluminum is naturally corrosion resistant, aluminum diamond plate is a favored choice for outdoor areas or other environments where the plate is in contact with water. Industrial kitchens, loading docks, and fire escapes often make use of aluminum diamond plate. The surface is able to withstand corrosion and abrasions, and can be easily cleaned.
Steel has the strength advantage over aluminum, making steel diamond plate even more hard-wearing and strong. For this reason, diamond plate made from steel is often used in structural applications such as stairs and ramps. While it offers less corrosion resistance than aluminum, steel diamond plate’s sturdiness holds up well through regular use and cleaning chemicals. It is ideal for indoor location usage such as shop floors and walkways.

Production of Diamond Plate
Although diamond plate may look intricate with its raised interlocking patterns, the process of making it is fairly straightforward. Using a combination of heat and pressure, metal can be made into diamond plate by stamping or hot rolling.
With the stamping method, the metal (generally aluminum) can be used at room temperature. The aluminum is run through a series of large rollers, with each pair of rollers having one raised side and one smooth. As the metal passes through each roller, the massive pressure of the patterned roller embosses those shapes onto the aluminum’s surface. Once finished, the diamond pattern will be firmly stamped into the raised side while leaving the other side smooth.
For steel diamond plate, hot rolling is the usual method of production. A steel slab is flash heated to just above its recrystallization point, and quickly passed through the rollers to produce the diamond pattern and desired thickness. Afterwards the steel is allowed to cool slowly, which helps prevent any major alternations to its mechanical properties. Once cooled to room temperature, the steel plate will have the raised diamond pattern on its surface.

Why Use Diamond Plate?
Diamond plate is most often found in any area where extra traction is needed to help reduce slips and falls. This safety practice applies most importantly to workers, but benefits their usage of industrial vehicles as well. A warehouse loading dock surface made of diamond plate keeps workers steady on their feet, but also provides better traction for forklifts. Finally, the extra strength and durability of the metal plate allows the dock to withstand the heavy weight of forklifts without damage.

Aluminum Alloy Tempering Methods

Newly forged metals are extremely hard – hard to a fault, because such a degree of inflexibility makes the metal very brittle. This applies even to alloys made of naturally ductile metals such as aluminum. However, after some type of tempering treatment is done to ease the tension within the metal’s structure, the aluminum will be left stronger and more resilient than before.

Before beginning, it’s important to determine whether the aluminum being tempered is heat-treatable or not. If the aluminum alloy belongs to one of the following series, it should not be heat treated:
Series 1xxx: pure aluminum
Series 3xxx: alloyed with manganese
Series 4xxx: alloyed with silicon
Series 5xxx: alloyed with magnesium
Pure aluminum and aluminum alloyed primarily with one of the elements in the list above do not respond to heat treatment. In these cases, the material can be toughened through other means such as cold working or work hardening.

For the other aluminum series, their tempering can be done through annealing, homogenizing, solution heat treatment, and aging. Aging can then be further split into two groups: natural aging, and artificial aging (also known as precipitation hardening). Whatever the method chosen, the purpose of tempering is to alter the aluminum’s physical and mechanical properties without changing its shape.

For aluminum series not considered heat-treatable, annealing is the method used to temper the metal. Work hardening means the metal is placed under repeated strain during use, which causes the grain structures within it to slide against each other. These stretched areas are called slip planes, and as the aluminum continues to be used, there will be fewer and fewer areas left that are not already slip planes. If the aluminum continues to be used without tempering, eventually the metal will be overworked and break.
The annealing process essentially performs a reset on the aluminum. By exposing it to a relatively low heat of 570 to 770 degrees F, the strain within the metal lessens as the crystalline grain structure returns to its original form. Once cooled, the aluminum can again handle the creation of more slip planes.

When casting aluminum parts using molds, the edges of the part will cool faster than the interior. This uneven cooling affects the structure of the part since some areas, particularly around the edges, will have grains of pure aluminum. The interior may be more combined with its alloying elements, but have remaining pockets of pure aluminum. Because pure aluminum is quite soft, this means those grainy areas will be weaker.
Homogenizing reduces this issue by heating the aluminum to just shy of its melting point, around 900 to 1000 degrees F, and allowing a gradual cooling. Unlike the heat of the mold, the uniform heat during homogenizing allows the internal structure to develop more uniformly. Once this is done, the cast aluminum part will be much sturdier.

Solution Heat Treatment
Solution heat treating is similar to annealing, but the metal is quenched rather than being allowed to cool on its own. When aluminum cools naturally, a greater degree of precipitation occurs. This means the alloying elements within the metal may drop out of place within the metal’s internal structure, rather than being as fully integrated as when newly forged. The sudden cooling from a quench means the alloying structure will be locked into place.
Depending on the type of alloy, the aluminum is heated to 825 to 980 degrees F, almost near melting point. This heat prompts the aluminum and alloying elements to better combine into solid solution. It is then immediately immersed in water to bring a sudden drop in its temperature. After tempering, the part will be stronger due to its improved homogenization.

After quenching, there is some precipitation which happens naturally in aluminum alloy. However, this is not a drawback – the alloying precipitation helps to reinforce and lock in place the aluminum’s microstructure. If left at room temperature, natural aging will continue to develop for up to 5 days, with most of the hardening taking place within the first 24 hours. This aging window means aluminum can be shaped after solution heat treating, leaving a much stronger piece after both processes are complete.
With artificial aging, the process of precipitation in some alloys may require a second round of tempering to reach its maximum strength. The metal is exposed to a fairly low temperature of 240 to 460 degrees F, just enough to encourage the alloying elements to begin to precipitate within the metal’s interior. It is then quenched again and allowed to finish cooling at room temperature. While more labor intensive, artificial aging will result in a significantly stronger metal in a shorter time period.

Aluminum Alloys for Anodizing

Anodizing the Aluminum Series

While aluminum is the most common metal to be anodized, not every grade of aluminum alloy receives this type of processing. As time passes, aluminum oxide naturally forms on the surface of aluminum, creating a layer of corrosion resistant protection. This layer not only halts continued oxidation and corrosion, it also helps reinforce the metal from the hardness of aluminum oxide.
However, this oxidation develops most successfully on pure aluminum – and pure aluminum is limited in its usage due to being a relatively soft and weak metal. Alloying the metal will give it greater strength and durability, but those properties come at the price of affecting aluminum’s ability to oxidize. Anodization is a convenient method of producing a thin, even layer of protective oxide on aluminum alloy.
Because anodization uses the metal’s aluminum content to form this anodic oxide layer, in theory any type of aluminum alloy can be used for this process. But some types of aluminum alloy have much greater chances of producing a successfully anodized piece. Due to the different element combinations in alloys, the anodizing of some series will produce much stronger and aesthetically appealing products than others.

Expected Results of Anodizing Aluminum Series
1xxx Series
This series covers pure aluminum, or aluminum with such tiny amounts of other elements that it can be considered virtually pure. 1xxx series can be anodized, but the pure metal remains weak and can be easily damaged. With or without anodizing, 1xxx aluminum is not strong enough for most structural applications.

2xxx Series
The primary alloying element for 2xxx is copper, which produces a very hard and strong type of aluminum. Anodization does not offer much additional protection, because the copper impedes the development of an anodic layer. The processing also gives the metal a yellow tint which consumers generally find unappealing.

3xxx Series
Manganese is the main alloying element in this series, and results in a layer of good-quality anodization. Unfortunately, the anodic layer is likely to be an unattractive brown tint that can vary from piece to piece, making it difficult to match when using multiple sheets in a project.

4xxx Series
Like the 3xxx series, the main alloying element in 4xxx causes the metal to turn an unappealing color after anodizing. 4xxx is alloyed with silicon, and this results in a dark gray anodized aluminum with sooty black patches. These blotches are very difficult to remove, so when 4xxx is anodized, it is generally used in architectural applications.

5xxx Series
This series is alloyed with magnesium, and is well-suited to anodizing. Once complete, the anodic layer is transparent, strong, and offers long-lasting protection. However, the chemical composition in some grades of 5xxx aluminum should be examined carefully, because some elements within may make anodizing a bit tricky. If the magnesium content is very high, or it contains over 0.1% silicon, the oxide layer may appear streaky.

6xxx Series
Both magnesium and silicon are the alloying agents in the 6xxx series, and these aluminum grades are considered to be excellent candidates for anodizing. The anodic oxide layer is clear and strong, as long as the alloy’s magnesium content is kept below a certain percentage. The strength of anodized 6xxx aluminum makes it a good choice for structural and mechanical applications, but its attractive finish means it can function well for aesthetic purposes too.

7xxx Series
Zinc is the primary alloying element in 7xxx series aluminum, and it takes well to the anodizing process. This series is already known for being some of the strongest types of aluminum, and anodizing increases that quality even further. The only risk comes if the chemical composition of the alloy is high in zinc. For 7xxx grades with heavy zinc content, the otherwise clear oxide layer can turn brown.

Ten Differences between Aluminum and Steel

At first glance, aluminum and stainless steel may appear similar: both a silvery gray, softly shiny, and used to make many of the same products. Many food service and kitchenware items, for instance, are made available from a manufacturer in both types of metals. What separates these two, other than price?

1. Thermal Conductivity
Aluminum is a metal with a high degree of thermal conductivity. What that means in real terms is that a water will boil more quickly in a stockpot than one made of stainless steel. However, aluminum also cools more quickly than stainless, so stainless will help keep a pot of soup warm longer.

2. Thermal Properties
Its lower degree of thermal conductivity means stainless steel is much more resilient to use in high temperatures. Aluminum will begin to soften around 400 degrees Fahrenheit; meanwhile, stainless steel can function well at temperatures up to 800 degrees. Some stainless steel grades can withstand temperatures nearly double that for short periods of work, up to 1500 degrees.

3. Strength
Both metals are quite strong and durable, but stainless steel more so than aluminum.

4. Strength to Weight Ratio
Stainless steel is very strong, but at the cost of a heavier weight. While aluminum is not as strong, manufacturing with this metal will result in an item nearly one third the weight of a steel part. This incredible strength to weight ratio makes aluminum very attractive to manufacturers, especially in the aerospace industry.

5. Welding
Most grades of stainless steel are relatively simple to weld, while aluminum’s high thermal conductivity makes it a more difficult task. However, both are among the most popular types of metals used in welding.

6. Electrical Conductivity
Aluminum has the distinct advantage over stainless steel here, with it being an excellent conductor of electricity. Stainless steel does not conduct electricity well in comparison to other metals.

7. Workability
Pure aluminum is a very soft and malleable metal, and even after alloying, it is easy to cut and form. Due to its strength and hardness, stainless steel takes effort to form into shape.

8. Corrosion Resistance
Both metals are known for excellent corrosion resistance. Chromium is one of the principal alloying agents in stainless steel, and boosts the corrosion resistance of the steel alloy. Aluminum is naturally resistant to corrosion on its own, although it is more vulnerable to damage from highly basic or acidic exposure.

9. Cost
In general, a part made of aluminum will be more affordable than the same item made of stainless steel.

10. Reaction to Foods
Consumers have the choice between aluminum and stainless steel cookware, and often make the decision to purchase aluminum based on price. However, aluminum is a more reactive compound than stainless steel. Acidic foods such as tomato sauces can leave aluminum damaged or with unsightly marks, while other foods like eggs can discolor if cooked or stored in aluminum. While both metals produce high-quality items, choosing stainless steel may be worth some additional money for non-reactive cookware.

What is a Non-Ferrous Metal?

If you were asked the definition of a non-ferrous metal, the answer may seem obvious: it’s a metal which contains no iron. And while that’s true, it might surprise you that the answer is not entirely correct! Non-ferrous metal is a sprawling category, which covers iron-free metals such as aluminum or copper. But a metal is also defined as “non-ferrous” when its chemical composition does not include a significant amount of iron. This means even an alloy with trace amounts of iron can be correctly identified as being made of non-ferrous metal. A ferrous metal will have iron as the first or second most-abundant element in its makeup. But if iron is present in a non-ferrous metal, it will typically be less than 1% of the metal’s overall composition.

So because the non-ferrous category covers so many different varieties of metal, it can be very difficult to identify common properties shared by them all. Some non-ferrous metals are very soft and ductile, while others are hard and brittle. One non-ferrous metal may be durable enough to weather freezing temperatures, but another is well-suited to withstand extremely high heat. However, there is one common denominator to be found amongst non-ferrous metals: they don’t rust. Since they contain very minimal to no iron, there’s little opportunity for the development of a significant amount of iron oxide. And that means the metal doesn’t show signs of rust.

However, it doesn’t mean non-ferrous metals are corrosion-free. In fact, some non-ferrous metals such as zinc are highly corrosive – much more so than iron itself! But because the term ‘rust’ only applies to the formation of iron oxide, non-ferrous metals technically do corrode but they don’t rust.

Common Non-Ferrous Metals
One of the most widely used non-ferrous metals, aluminum in its pure form is soft and not particularly strong. Once alloyed, it gains strength and durability while remaining relatively lightweight. These assets, along with its machinability, makes it very popular in manufacturing. Common applications for aluminum range from aircraft fuselage and cars, to drink cans and kitchen utensils.

Like aluminum, unalloyed copper is softer and less strong in comparison to carbon steel. One of its most desirable qualities is its high thermal and electrical conductivity, which is why pure copper is commonly found in wiring and high-end cookware. When alloyed with zinc, it forms another non-ferrous metal, brass. Brass is stronger than copper, while retaining a high degree of malleability. This makes it popular for fittings and castings in a variety of shapes. Copper can also be alloyed with tin to create bronze – again creating a stronger and harder metal than the original copper, with better durability. Given the toughness of bronze parts, it’s a popular choice to manufacture bearings, electrical connectors, and springs.

Zinc is a non-ferrous metal with a low melting point. As mentioned before, it is more likely to corrode than iron. However, the type of corrosion produced by zinc is beneficial: the zinc oxide which forms on the layer of the metal stops any further corrosion from reaching inside. For this reason, of the most common uses for zinc is in galvanizing other metals. The outer layer of zinc forms a protective coat on steel or iron to prevent rust.

Common Metals That Don’t Rust

When it comes to protecting and maintaining metal, the most constant battle encountered will be against rust. Rust compromises a metal’s chemical characteristics, eventually leading to its disintegration. And even if it doesn’t progress to a destructive point, it’s just not very appealing on an aesthetic level. The distinctive orange-brown of rust forming on metal can make it look old and shabby long before its time. So one of the best solutions to this problem is to eliminate it from the start: choosing a metal that won’t rust.

Common rust-free metals include:

  • Aluminum
  • Stainless steel
  • Red metals (copper, brass, and bronze)
  • Galvanized steel


Aluminum and aluminum alloys cannot rust because they contain no to very little iron, and ‘true’ rust is made up of iron oxide. That doesn’t make aluminum indestructible, since it can still oxidize when exposed to water. But unlike iron oxide which will wear away at the underlying metal, the forming of aluminum oxide actually becomes a protective barrier. Once it develops on the aluminum’s surface, the oxide layer will be quite resistant to any additional corrosion.

Stainless steel

Most grades of stainless steel include at least some amount of iron, the element which leads to rust. However, the other alloying elements – particularly chromium – lends it protection to the material. Chromium tends to oxidize very quickly and like aluminum, the resulting oxide then forms a barrier against rust. With this chromium oxide layer in place, oxygen is no longer able to reach and react to the metal underneath. Other alloying elements in stainless steel such as nickel and molybdenum provide resistant to rust development.

Copper, brass, and bronze

Collectively known to as “red metals”, these metals can oxidize without rusting since they contain virtually no iron. Copper is very slow to react to oxygen and other environmental factors, but once corrosion does occur it will gradually turn the bright reddish metal to a verdigris green patina. Brass and bronze are copper alloys, with the dual benefits of copper’s own corrosion resistance and the rust-free properties of alloying elements. Both brass and bronze are even more resistant to corrosion than pure copper.

Galvanized steel

Unlike the other three types mentioned, galvanized steel relies upon the application of a physical barrier to prevent rust. Carbon steel is galvanized after being coated with a thin layer of zinc. After bonding with the surface, any oxidation which does occur becomes zinc oxide. A zinc layer exposed to water will become zinc carbonate, which is water-insoluble and puts a stop to any further chemical reactions. More importantly, whatever oxidation that takes place will affect the wear of the zinc before reaching the steel underneath.