Difference between AISI 1008 and 1018 Seamless Steel Pipes

If you are a manufacturer who has just ventured into the world of seamless pipes manufacturing, you have a lot to learn. The first important step of the process is to choose the correct material. While some pipe producers prefer carbon steel, some produce stainless seamless steel pipes and tubes.

Stainless steel is the ideal material for producing pipes because the metal has some unique properties that no other metal alloy has. Also, stainless steel is easy to mold. Hence, you can give them the desired shape effortlessly.

Now, there are different steel grades from which you need to choose one or more. Today, we will discuss two of the most commonly chosen steel grades so that you can decide which one suits your needs. These two steel grades are AISI 1008 and AISI 1018. If you are looking for steel grades with fewer carbon elements, these two are the best choice. Hence, you can use these two steel grades to produce pipes that you can use in multiple applications.

Before choosing a steel grade, as a seamless pipe manufacturer, you should know the properties, chemical composition, strength, and application of the steel grades. Their physical properties play a critical role in choosing among many steel grades.

So, let us check out the different properties, differences, similarities, and applications of the steel grades AISI 1008 and AISI 1018.

Difference between the two steel grades:

AISI 1008 and AISI 1018 have a lower percentage of carbon. Therefore, the pipes you manufacture from these two steel grades have multiple applications. For example, if you want to build automotive parts, you should choose one of these two steel grades. Similarly, both steel grades can be used in machine parts and construction materials.

However, there are some differences between these two steel grades. We have discussed the differences below:

• Chemical composition:
• The primary difference between AISI 1008 and AISI 1018 must be their chemical composition. The AISI 1008 steel grade comprises 0.50% copper, 0.40% sulfur, 0.30% manganese, and 0.10% carbon.

On the other hand, AISI 1018 steel grade comprises 0.04% maximum phosphorus, 0.05% maximum sulfur, 0.14% to 0.20% carbon, and 0.60% to 0.90% manganese.

As you can see, the chemical composition of these two steel grades is significantly different from each other. Therefore, seamless tube suppliers often choose one based on the chemical compositions of the steel grades.

• Properties:
• If you are aware of mild steel and carbon steel, you will understand that AISI 1008 is mild steel because of the low content of carbon. You can use AISI 1008 steel grade for cold rolling steel trips and tubes. Even though AISI 1008 steel grade has excellent weldability, it does not have better bendability and malleability.
• On the other hand, AISI 1018 steel grade has a medium carbon percentage, making it stronger than AISI 1008 steel. The carbon content in this type of steel is around 0.18%. You can produce both hot-rolled pipes and cold-drawn tubes with this steel. It has better weldability, machinability, and formability.
• Application:
• The primary application of AISI 1008 is in the forming, shallow, stamping, and drawing processes. Seamless pipe manufacturers use this steel type for manufacturing components of automobiles, office equipment, appliances we use in households, and many more.
• AISI 1018 steel grade, on the other hand, is ideal for manufacturing bolts, gears, pins, shafts, studs, etc. You can also use this steel type for applications requiring high strength, toughness, and flexibility.
• Machinability:
• Both steel grades have highly tensile properties. Hence, these steel grades are machinable. Therefore, you can safely use these steel grades for higher precision applications.
• However, AISI 1008 has less machinability than AISI 1018 between the two steel grades. You can drill the seamless tubes and pipes you produce from AISI 1018. Also, you can mill and turn the pipes per the requirements of the clients. Depending on how complex the application is, you can choose between the two steel grades.
• Toughness and strength:
• When it comes to toughness and strength, one of the two steel grades becomes the better choice for producing seamless pipes. You can guess by now that we are referring to AISI 1018. Since the carbon content is more in AISI 1018 steel grade, it is stronger, more robust, and tougher than AISI 1008. Due to its low strength and toughness, you cannot use 1008 steel grade to produce mechanical parts.
• You require AISI 1018 steel grade to produce mechanical parts that you can use in automobiles because these parts are subjected to constant pressure. On the other hand, if you want to produce pipes that you can use for their mechanical properties, you should choose AISI 1008. Even though the steel grade is not as strong as AISI 1018, it offers much better machinability, as you know from the previous point.
• Affordability:
• By now, you may already have an idea about the affordability of the two steel grades. It is obvious that steel grade AISI 1008 will be more affordable than AISI 1018 because of the lower percentage of carbon present in the alloy. Therefore, when seamless tube suppliers decide which steel grade they need to produce pipes and tubes, they consider the application of the pipes and tubes. For instance, you can produce pipes using steel grade AISI 1008 if you do not need the pipes to be more robust or exhibit more toughness. Using the more affordable steel grade will incur less expense for you and your client.
• On the contrary, if you require pipes that must withstand stress, you should choose AISI 1018 steel grade. Making the right choice can save you money.
• Thermal properties:
• There is practically no difference in the thermal properties of both steel grades. Both AISI 1018 and 1008 have a melting point range of 2600° to 2750°F or 1450° to 1510° C.

The findings:

Now that you are done with understanding the different properties of both AISI 1008 and 1018 steel grades, you can understand that they have multiple applications. To summarize, we can say that even though a few characteristics of both these steel grades match, their chemical and physical properties are quite distinct from each other. As a result, their machinability, strength, malleability, etc. vary. Hence, you cannot use these two steel grades interchangeably. Instead, both of these have significant applications.

Depending on where and why you want to use the seamless pipes and tubes, you can choose either of the two options. If you are still deciding which material to choose, you can contact a renowned manufacturer with experience so that they can guide you.