Carbon Steel vs Aluminum

Carbon steel and aluminum are two of the most common metals in manufacturing today. Still, they differ significantly in how they are made, their use, and their general properties. In this article, we’ll compare carbon steel and aluminum so that you can decide which material will work best for your pneumatic conveying system.


What is Carbon Steel?

Carbon steel is a versatile iron-carbon alloy made by heating iron and carbon together. Because it’s easy to work with and relatively inexpensive, carbon steel is used in many industries to make everything from auto parts and construction beams to electrical wiring and tools that require high strength properties and wear resistance. 

Carbon steel can be graded with either a low, medium, or high-carbon steel content, with the amount of carbon in the steel determining its strength, flexibility, and hardness. 

  • Low-carbon steel is characterized by low hardness while staying highly flexible and tough. 
  • Medium-carbon steel also has a low hardness and lower flexibility but has increased strength and toughness. 
  • High-carbon steel has the highest hardness and strength rating but is also inflexible and brittle. 

In general, the more carbon in the metal, the stronger it will be, but too much carbon makes the steel fragile. Manganese, cobalt, silicon, and chromium are common elements added to carbon steel to create different carbon steel variants. Regardless of type, however, all carbon steels are vulnerable to corrosion.


What is Aluminum?

Aluminum is a silver metal made from bauxite ore. It is stronger and more malleable than copper and 2.5 times lighter than carbon steel. Additionally, aluminum has a higher melting point than carbon steel and can withstand intense heat without warping or melting. It is an excellent conductor of electricity, rating second only to copper. Abundant and low-cost, this malleable metal is also one of the lightest on the planet, with the highest strength-to-weight ratio of any metal. 

Unlike carbon steel, aluminum has excellent corrosion resistance properties. This resistance doesn’t mean it's impervious to rust, however. Aluminum can corrode when exposed to direct water or chlorine bleach. However, it can be minimized by applying a protective coating to the aluminum to protect it from direct exposure.


Which is Better?

The decision on whether you should go with a pneumatic conveying part made from carbon steel or aluminum depends on what the part will be used for, what type of system it will be used in, and what elements the system will be exposed to.

Take pneumatic conveying elbows, for example: because aluminum elbows are made from a softer material, they wear out quickly when exposed to abrasive materials such as plastic pellets. In this case, you’re better off using carbon steel elbows as they are durable and abrasion resistant. If, however, the materials you’re transporting are non-abrasive plastics or if you’re using air-only conveying lines, aluminum elbows will be a cheaper alternative.

Carbon steel parts are generally durable, economical, readily available, and reasonably priced. Their corrosion vulnerability can be mitigated by painting parts out in the elements or areas where rust is a concern. 

Aluminum parts are naturally corrosion resistant, and because they are 2.5 times lighter than carbon steel, they are easier to use and quicker to fasten. They are more expensive than carbon steel parts, and their tendency to wear down quickly in the wrong environment may become costly in the long run.


As you can see, both carbon steel and aluminum are excellent materials for pneumatic conveying systems. Which one you use will depend on which unique properties make them suitable for your project. If you need a bare elbow, a Ceram-Back®, or any one of our other abrasion-resistant options, contact us to get a quote. At Progressive Products, if you can imagine it, we can make it happen.

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