Carbon Fiber VS Steel: Which Is Stronger?

Steel has long been used to create sturdy, long-lasting, rigid structures. Carbon fiber is a relatively recent addition to structural materials, but its properties are impressive and unique. The following is a breakdown of the properties of these two materials and some examples of industries that are moving to carbon fiber. 

What is Carbon Fiber?

Carbon fiber is composed of carbon, a naturally occurring element, and has high tensile strength due to its crystalline structure.  It is used to fabricate high strength, lightweight composite parts with the fiber embedded in a polymer matrix. The physics of carbon makes it very strong and incredibly rigid. The modulus of elasticity (a measurement of a material’s resistance to deformation) for carbon fibers is between 150-760 gigapascals (GPa). The wide range is because the manufacturing process can be modified to tailor stiffness and strength.  The tensile strength of carbon fiber is one of the highest of any material available. Although many materials, including steel, can have high stiffness and tensile strength, the real benefits of carbon fiber are its strength-to-weight ratio and stiffness to weight ratio due to its low density (around 1.6 g/ cm3). This enables carbon fiber materials to have a high tensile strength while being lightweight. As such, it  is an ideal candidate for industrial applications such as: 

  • Robotics
  • Metrology
  • Terrestrial vehicles 
    • cars
    • trucks 
    • bikes 
  • Wind turbines 

In many of  these applications, heavier materials consume more energy, cause greater wear over time, and/or make high performance designs difficult to impossible.

How Does Steel Compare?

Steel has been a go-to material for a long time because of its high modulus of elasticity of around 200 GPa. This rigidity, and its relative abundance, have made it a ubiquitous material for manufacturing.  But at a density of about 8 g/cm3 its weight can be very taxing on the machines it is meant to strengthen. This is about 5 times the weight of carbon fiber materials that would provide the same rigidity or better. 

What Are Some Common Applications of Carbon Fiber?

Carbon fiber can be used to produce a wide variety of products. Anything that needs to be rigid and lightweight is a perfect candidate for carbon fiber composite materials. They’re popular options for phone cases, since they offer great levels of protection from damage. They are being used increasingly in drones and unmanned aerial vehicles (UAVs) where the low weight contributes to a lighter structure and greater payload. In the automobile industry, new advancements in carbon fiber technology have the potential to cut the car’s weight nearly in half. Also, carbon fiber doesn’t suffer from thermal expansion of steel or aluminum. Medical imaging tables benefit from carbon fiber’s  strength and stiffness, maintaining critical dimensions under load without breaking down over time, even after high doses of x-ray and gamma radiation.

How Easy is Carbon Fiber to Cut Compared to Steel?

Carbon fiber is easier to cut than steel. Its low weight facilitates handling and Rotary wheels or saws with diamond or tungsten-carbide blades easily cut carbon fiber composite and make prototyping easy.

While steel is a reliable material, the constant advancements in carbon fiber manufacturing make this material an ever-evolving source of innovation. Design a carbon fiber prototype with Element 6 Composites and bring your design to life.