Aluminum Alloys

A Guide to the Most Popular, All-Purpose Aluminum Alloys


Aluminum is no doubt one of the most popular metals, shaping the capabilities of our modern world. Aluminum alloys make a wide range of in-demand products possible. HVAC, smart phones, automotive parts, and marine gear all require them. Scientists, architects, and designers prefer aluminum for many reasons including high strength-to-weight ratio, flexibility, and energy savings.

What Makes Aluminum So Popular?

After 1886—when the method for commercially producing aluminum was first introduced—aluminum has grown tremendously in popularity. This is in large part due to the needs of our modern lives and the versatility aluminum offers. Let’s use the automotive industry as a primary example.

The automotive industry is huge and revolves around the production of 95 million cars and trucks each year. At the same time, the desire for more efficient ground transportation is higher than ever. The need for lower vehicle weight, reduced emissions, and improved fuel economy has sparked intense interest in aluminum.  Aluminum offers a one-two punch; it is lightweight without sacrificing strength. In fact, some aluminum alloys are as strong as structural steel.

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Kloeckner Metals is a full-line aluminum supplier and service center. Download our aluminum spec sheet to see what Kloeckner Metals routinely stocks.

Aluminum Spec Sheet

Aluminum’s versatility goes beyond its weight and strength. It’s easily workable into any form and can take on an impressive variety of surface finishes. Under most service conditions, aluminum shows high resistance to corrosion. Excellent machinability is one of the key factors influencing the low cost of finished aluminum parts. Almost any method of joining—riveting, welding, or brazing—applies to aluminum. Aluminum sheet can be drawn, spun and roll formed.

Aluminum is also one of the most recyclable materials. For example, in as little as 60 days, the aluminum beverage can you just finished drinking out of could be recycled and reshelved. That’s amazing!

However, much of aluminum’s versatility is owed to specific alloying elements. Pure aluminum is soft and demonstrates only moderate strength. Therefore, most applications for aluminum require aluminum alloys.

How to Classify Aluminum Alloys

Aluminum alloys are often broken down into three categories: wrought heat treatable, wrought non-heat treatable, and casting alloys.

Wrought Non-Heat Treatable Aluminum Alloys

This group includes high purity aluminum and the wrought alloys in the 1xxx, 3xxx, and 5xxx series. Wrought non-heat treatable aluminum alloys are hardened primarily by cold working.

Wrought Heat Treatable Aluminum Alloys

Heat treatable alloys have copper, magnesium, or zinc as their primary alloying element. These are the 2xxx, 6xxx and 7xxx series alloys. Wrought heat treatable aluminum alloys can be precipitation hardened. This process develops high strength levels.

Aluminum Alloys for Casting

This group includes both non-heat-treatable and heat treatable alloys. The most common aluminum alloys for casting are the 2xxx, 3xxx, 4xxx, 7xxx, and 8xxx. Strength properties obtained through casting are not as high for wrought heat treatable alloys.

List of Aluminum Alloys

The Aluminum Association describes how there are more than 530 registered active compositions of aluminum alloys and that number continues to grow. They’re also available in various formats including sheet, plate, tube, and bar. That’s a lot of aluminum alloys!

Given widespread applications across industries, selecting the right aluminum alloy type for a specific end-use is crucial. Just slight differences in chemical properties can drastically alter strength, workability, corrosion resistance, and electrical conductivity of the alloy.


With a purity of 99.0% or greater, 1100 is often called commercially pure aluminum. It is the softest of the common alloys.

  • 1100 aluminum is non-heat treatable, extremely malleable and shows excellent corrosive resistance. Though 1100 aluminum has great weldability, it also has a rather narrow melting range to consider.
  • Good machinability when hard tempered.
  • 1100 aluminum is frequently used for electrical work, food and chemical handling, dials and name plates, spun hollow ware, lighting, HVAC, heat insulators and license plates.
  • Kloeckner Metals supplies 1100 aluminum sheet.


3003 aluminum is the best known and most widely used of the common alloys. 3003 aluminum is non-heat treatable. With about 20% more strength than 1100, 3003 is a practical general-purpose aluminum for moderate strength applications.

  • Alloyed with manganese, 3003 aluminum demonstrates good formability, workability and drawing characteristics.
  • It’s inexpensive, can be welded and brazed by all methods, excellent corrosion resistance, and has a uniform appearance.
  • You’ll find 3003 aluminum in everyday products like cooking utensils, food containers, hardware, and cabinets. Other common applications include: chemical equipment, pressure vessels, piping, awning slats, trailer and truck panels, and general sheet metal fabrication.
  • Kloeckner Metals supplies 3003 aluminum sheet.


3004 aluminum is very similar to 3003 aluminum in its composition and end-uses. However, 3004 shows more strength due to a 1% addition of magnesium.

  • As with all 3xxx aluminum alloy series, 3004 aluminum is non-heat treatable.
  • Just a slight addition of magnesium gives 3004 strength approaching that of 5052 aluminum.
  • Storage tanks, pressure valves, and cookware are all appropriate end-uses.
  • Kloeckner Metals supplies 3004 aluminum sheet.


Though 3105 is non-heat treatable, it can be annealed during cold working.

  • 3105 aluminum has slightly higher strength than 3003 aluminum, others properties are similar to 3003 aluminum alloy.
  • 3105 aluminum’s corrosion resistance, formability and welding characteristics are excellent.
  • Less critical building applications, such as roofing, siding, flashing and duct-work are more common for 3105.
  • Kloeckner Metals supplies 3105 aluminum sheet.


5052 is the strongest non-heat treatable sheet and plate in common use. Versatility and strong value make it one of the most serviceable alloys.

  • Alloyed with magnesium, 5052 aluminum can be anodized. It shows good welding characteristics, and demonstrates moderate-to-good strength. It has good drawing properties and a high rate of work hardening.
  • 5052 aluminum is resistant to saltwater corrosion, making it appropriate for many marine applications.
  • Applications range from fuel tanks to marine applications, fans, fan blades, fencing, small boats, truck trailers, architectural panels, and some non-critical automotive parts.
  • Kloeckner Metals supplies 5052 aluminum sheet and 5052 aluminum plate.


6061 is one of the strongest aluminum alloys. It is considered the least expensive and most versatile of the heat treatable alloys. Though less formable, it is commonly extruded.

  • Alloyed with magnesium and silicon, 6061 aluminum is heat treatable, can be anodized, and hardened after forming. After heat treatment, its strength is equal to low carbon steel.
  • Outstanding surface quality, better corrosion resistance than steel, and a high strength to weight ratio.
  • You’ll see 6061 applied in architecture and construction. Additional applications include: structural framing, moldings, fire ladders, welded assemblies, sail boats, electronic parts, bridge components, piping, valves, and fasteners.
  • Kloeckner Metals supplies 6061 aluminum plate, bar, and tube.


6063 aluminum is mainly an extrusion alloy used almost exclusively by the architectural applicators. It is heat treatable for strengthening.

  • Like 6061 aluminum, 6063 is alloyed with magnesium for added strength, and silicon to reduce melting temperature. This makes it excellent for anodizing.
  • With similar composition and mechanical properties to 6061, two of the main differentiators of 6063 aluminum is its superior surface finish and poor strength-to-weight ratio.
  • Common applications include: electrical components and conduit, pipe and tube for irrigation systems, door frames, railings, furniture, appliances, boats, and motor vehicles.
  • Kloeckner Metals supplies 6063 aluminum bar and tube.

Where are Aluminum Suppliers Near Me?

Kloeckner Metals supplies aluminum nationwide from 15 branches in the United States and Mexico. Please visit our branch directory and use our filter tool to see which branches supply the type and grade of aluminum you require for your business needs.

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Kloeckner Metals is a full-line aluminum supplier and service center. Kloeckner Metals joins a national footprint with the latest fabrication and processing technologies and innovative customer service solutions.

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Natalie Spira
Natalie Spira is Kloeckner's Acquisition Marketing Manager. Previously, she was the Founder and CEO of Fraction Marketing, a marketing agency providing fractional support to scaling startups with a focus on acquisition marketing and demand generation. Natalie holds a MBA from Tel Aviv University with concentrations in entrepreneurship and marketing and a BA in English from UCLA.


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