Aluminum Sheet Products Versus Aluminum Plate
Today, aluminum materials make up 75 to 80 percent of a modern aircraft and aluminum has been used in that capacity since the birth of powered flight.
In fact, even before the Wright Brothers first successful flight in 1903, Count Ferdinand Zeppelin used aluminum to make the frames of his airship that flew for the first time in 1900. And a few years later, the famed brothers from Dayton built a lightweight aircraft engine using a cylinder block and other parts made with aluminum.
The reason for this is that aircraft requires building material that is inherently strong and lightweight.
And aluminum has fit the bill beautifully since the dawn of manned flight.
Looking at Aluminum: Sheets and Plates
Because aluminum aerospace parts are about one third the weight of steel, which allows aircraft to carry more weight and be more fuel efficient than they could be if built with heavier material. In addition, the high corrosion resistance of aluminum is essential for aircraft safety.
Aluminum parts are made from a variety of alloys grades of material and of different methods of production. These different alloys and grades are used for particular aerospace applications.
Here are a few of the more common grades and uses:
- 2024 is typically used for cowls, aircraft skins, and common aircraft structures, as well as for repair and restoration. It is also the most common alloy used.
- 7075 is a high-strength alloy and used to strengthen aircraft structures. It is also one of the most common aviation industry grades after 2024.
- 5052 is an aluminum grade often used for fuel tanks because of its excellent moisture and corrosion resistance.
- 3003 grade aluminum sheet is commonly used for cowls and baffle plating.
While aluminum can be formed as blocks, rods, and bars, two of the most common forms used in the aerospace industry are sheets and plates.
Aluminum Sheet and Aluminum Plate
Aluminum sheets and plates start with ingots of raw aluminum which are preheated before processing. Once the ingots are properly heated, the aluminum is fed into a breakdown mill and then formed into a thick sheet.
From here, the sheet is rolled repeatedly until it is reduced to a thickness of just a few inches. After the rolling process, the rolled aluminum sheet is wound into a coil and cooled by passing them through several cold rolling mills. The cold rolling of the aluminum sheet is the final step of the process.
As aluminum moves between rolls under pressure, it is reduced in thickness to create plate or sheets. Aluminum plate metal is .250 inches and thicker, while aluminum sheet is typically defined as a piece of metal that is less than .249 inches thick.
Sheet is the form of aluminum that is used the most often. In addition to the aerospace industry, aluminum sheet is used in manufacturing various types of containers for the packaging industry. It is also commonly used in tractor-trailers and automobile body panels, for cookware and appliances, as well as building products for siding, awnings, roofing, gutters, and carports.
Sheet aluminum can be treated with color anodizing etched for matte finishes, or polished to a reflective finish, common in aircraft applications.
Aluminum plate is the most often used in the aerospace, transportation, and military industries for heavy-duty applications. A unique attribute of certain aluminum alloys is their ability to become stronger at extremely cold temperatures. Because of this, aluminum plate is used for the skin of spacecraft fuel tanks and jets, as well as storage tanks.
In addition, the high resistance to corrosion, its light weight, and its high strength, makes aluminum plate a common material for the structural sections of ships and railcars, as well as for military vehicle armor and even body armor..
Aluminum sheet and plate are widely used and in demand due to light weight, strength, high corrosion resistance, workability and versatility of aluminum alloys.
The Trouble With Standards
Historically, the standards used to specify the thickness of metal wires – gauges – were also used to designate different thicknesses of sheet and plate. This was before new, more accurate measurement technology was developed.
According to an article at ConspectusInc.com,
“It has been years since industry standards have abandoned gage to designate metal thickness, now the standards rely on decimal inch thickness instead.
Some standards attempt to help with the conversion. These standards use exact decimal thickness as the standard, permit rounded mil thickness, and then show the equivalent gage. Gage thicknesses are included for reference only, not as the standard.”
In fact, the American Society for Testing and Measurement (ASTM) says in specification ASTM A480-10a,
“The use of gage number is discouraged as being an archaic term of limited usefulness not having general agreement on meaning.”
The common practice today is to specify the exact thickness of the metal, though the gauge may also be listed. The standard thicknesses (and gauge) for aluminum sheet and plate is found in the Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate: ASTM B209-14.
Contact Your Industry Experts for Aluminum Sheet and Plate
Regardless of whether you need 100 sheets of aluminum product, 100 square feet of plate, or just a few feet of stainless-steel tubing, AAA Air Support promises to always ship out your part orders quickly and efficiently.
Our goal always is to provide your company with the means to complete that project or get that airplane back in the air in AOG situations.