1018 Carbon Steel: Characteristics, Uses, and Material FAQs
1018 carbon steel is a low-cost steel alloy that is really easy to machine and weld. It’s a go-to for many companies across industries, and it is probably the most common low-carbon steel that we work with. It is a great choice for prototyping, general fabrication, and high-volume production alike.
At Rapid Axis, we’ve worked on a number of 1018 carbon steel projects, and our experts will explain how it works, its characteristics, common uses, and general information you need to know about 1018 steel.
What Is 1018 Carbon Steel?
1018 carbon steel is an alloy of steel that has a low amount of carbon, and falls into the 10xx family — the 18 at the end signifies a carbon content of roughly 0.18%. With such a low amount of carbon, manganese, sulfur, and phosphorus, 1018 steel is easy to machine, weld, and offers a good surface finish.
1018 is an example of “mild” or “plain carbon” steel. It doesn’t have the corrosion resistance of a 304 stainless steel, but it also has a much lower price tag which makes it a common metal to use.
In Europe, you might see it called C15E (1.1141), in Japan 1018 is often sold as S15C, and China brands this alloy as “15 steel”. No matter the name, you’ll be dealing with the same alloy that comes in a variety of shapes.
1018 carbon steel is commonly found in flat sheets, plates of varying thicknesses, square or hex bars, cold-drawn or hot-rolled round bars, and cut-to-length blanks of common shapes.
Applications
Like other carbon steels, there are some common applications for 1018 steel:
Pins and shafts
1018 is a low-cost way to create pins and shafts that can withstand forces before yielding. For higher-stress applications, you’ll need to consider a different alloy.
Fixtures and welded frames
Since 1018 is so weldable, companies will use this steel for welded frames or a variety of custom fixtures.
Machined housings
1018 carbon steel is easy to machine, making it a good choice for CNC-machined housings.
Pins and bolts
This steel offers good wear resistance, making it a good candidate for low-load fasteners like pins and bolts.
Bases and plates
A lot of machine bases use painted or coated 1018 carbon steel since it is affordable and easy to weld and work with.
Strengths and Limitations of 1018 Carbon Steel
1018 is a universal alloy, but what makes this material so versatile? It has a number of strengths as well as some limitations to keep in mind before your next order:
Strengths:
- Great machinability. As a softer steel, 1018 machines easily without excessive wear on tools. We don’t even need specialty tools to make parts out of this alloy.
- Really good weldability. 1018 carbon steel is surprisingly easy to weld, and it doesn’t require the same preheating or post-treatment that other steel alloys require.
- Impressive ductility and toughness. Cold-rolled 1018 offers good ductility and toughness, making it a good option for long-lasting parts.
- Affordable and widely available. There are so many options and sizes available for stock 1018 steel, and the price is low for the raw material. This makes 1018 a low-cost way to get steel parts in any shape you’d like.
Limitations:
- Poor corrosion resistance. The biggest downside of 1018 carbon steel is that it is susceptible to corrosion, so it will rust over time. If you’re working in harsh environments, carbon steel parts will rust without a powder coating or plating treatment.
- Not as strong as other alloys. There are a number of other steel alloys that are stronger and are better candidates for use in load-bearing or high-impact applications.
- Not great for heat treatment. With such a small amount of carbon, 1018 steel is very difficult to heat treat beyond just a standard surface hardening.
Metals Similar to 1018 Carbon Steel
Before deciding on 1018 carbon steel for your next project, consider some other steels that are comparable to see which is the best option.
1045 steel
has more carbon, so it offers higher strength and better wear resistance.
A36 steel
is a lower-cost structural steel that is ideal for high-stress parts.
1215 steel
is a better option for smaller, simpler parts since it has better machinability.
4140 alloy steel
is a lot stronger and is used when fatigue resistance is paramount.
304 stainless steel
has better corrosion resistance and chemical resistance, but it is more expensive and more difficult to work with.