Category: Aluminum

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.

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.

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.

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.

Annealing
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.

Homogenizing
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.

Aging
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.