When to Use Carbon Steel vs Stainless Steel

More elastic than rubber and 1,000 times stronger than iron, steel gets used in almost every industry. It’s one of the world’s most environmentally friendly materials because it’s easy to recycle and lasts practically forever.

Essentially an iron alloy, steel is at least 3,000 years old, and blacksmiths worked in steel as early as the 13th century. Today, the steel industry employs more than two million people and fuels a $290 billion sector of global business.

Steel comes in two basic types — carbon and stainless.

What is Carbon Steel?

Most of the steel produced throughout the world is carbon steel.

Like all steel, carbon steel is a metal composed of iron and carbon. Carbon steel may also contain other alloys such as chromium, silicon, nickel, or vanadium; but these additives are uncommon.

The American Iron and Steel Institute defines carbon steel as “Steel that has properties made up mostly of the element carbon and which relies on the carbon content for structure.”

Typically, the carbon component makes up between .12 and 2 percent of the alloy, and the remaining non-ferrous ingredients do not total more than 10.5 percent of the product.

The higher the carbon content, the denser and more brittle the steel. An alloy with lower carbon content, though, offers a tougher, more flexible metal.

But there’s more to it than that. Adding additional compounds like nickel or chromium increases the steel’s corrosion resistance and adds toughness and durability to the product.

Carbon steel comes in three grades — low-carbon, medium-carbon, and high-carbon. Each grade of steel is progressively stronger and more expensive.

Most manufacturers use low-carbon steel because it’s more malleable and easier to weld than higher-carbon alloys. Products made with it retain their shape well despite the force of insults they experience.

In general, carbon steel is solid and resistant to abrasion.

What is Stainless Steel?

Grades of steel that contain more than 10 percent chromium — with or without other alloying elements — are called stainless steel. This form of steel is popular among manufacturers because the chromium reacts with oxygen to create a protective layer that resists corrosion. Consequently, stainless steel makes a reasonable option for items to be used in wet environments.

Stainless steel also holds its strength even when exposed to high temperatures. This metal alloy can withstand temperatures of up to 1700° F for lower grade and up to 2100° F for the high-temperature stainless grade.

Stainless steel comes in five common grades:

• 304 — More than half the world’s stainless steel is type 304. Available in many forms and finishes, type 304 gets widely used in architecture, chemical plants, and food processing environments. Kloeckner Metals supplies 304 stainless steel sheet, 304 stainless steel plate, 304 stainless steel bar, and 304 stainless steel tube.
• 316 — This carbon steel type contains 2–3% molybdenum, an essential trace mineral. As a result, type 316 is more resistant to deterioration than type 304. Kloeckner Metals supplies 316L stainless steel sheet, 316L stainless steel plate, 316L stainless steel bar, and 316L stainless steel tube.
• 409 — Suitable for high temperatures, type 409 contains the highest concentration of chromium of all stainless steels. It is also the least expensive of the materials. This grade is stocked in the following formats: 409 stainless steel sheet, 409 stainless steel plate, 409 stainless steel tube.
• 410 — Exceptionally strong, type 410 stainless steel is a low-cost, heat-treatable grade often used in non-severe corrosion applications.
• 430 — This corrosion-resistant type of stainless steel sees wide use in decorative applications. Kloeckner stocks 430 stainless steel sheet.

Comparisons

What is the chemical composition of carbon steel vs stainless steel?

Simply put, carbon steel contains less than 10.5 percent chromium, and stainless steel contains more than 10.5 percent chromium.  The chart below details the chemical breakdown of carbon and stainless steel.

What are the mechanical properties of carbon steel vs stainless steel?

The mechanical properties of steel vary based on the alloy’s carbon content. The chart below provides a general representation of the relative merits of each kind of steel.

While technically possible, stainless steel and carbon steel rarely get welded together because the two metals have different levels of electrical conductivity.

Where will you find carbon steel vs stainless steel?

Carbon steel gets used in a variety of industries and sectors depending on the grade of the steel. Although used in automobiles since the 1930s, stainless steel mostly goes into products for the medical technology, architecture, and food and beverage industries.

Typical applications of carbon steel

• Low-carbon steel — Used in pipes, food cans, bridges, and automobile body components.
• Medium-carbon steel — Used in train wheels, crankshafts, railway tracks, or wherever strength and toughness is required.
• High-carbon steel — Used in cutting tools and where the strongest carbon steel is required.

Typical applications of stainless steel

• Clean and sterile environments such as medical device manufacturing and medical laboratories.
• Transportation manufacturing such as vehicles and airplanes.
• Food and catering where it’s often used in cookware and cutlery.

When considering whether to go with carbon steel vs stainless steel, look at your needs and your budget. For help selecting the right kind of steel for your project, contact an expert at Kloeckner.