304 vs 316 Stainless Steel: Choosing the Right Grade for Your Project

304 vs 316 Stainless Steel: Choosing the Right Grade for Your Project

Stainless steel has been an important material in many projects since it was first manufactured in the 20th century due to its strength, flexibility, and ease of machining and welding. Stainless steel contains different levels of metal elements and therefore comes in different grades. There are differences between the different types of stainless steel, and the comparison between 304 and 316 is as old as stainless steel itself.

Both steels, SS 304 and SS 316, are austenitic and are used in different ways in rapid prototyping methods such as CNC machining and sheet metal fabrication. But when comparing 304 and 316 stainless steels, you need to consider the project at hand and understand the properties of each. To help you choose the right grade, this article describes the features, benefits, and uses of stainless steel 304 and stainless steel 316. The full differences between Stainless Steel 304 and Stainless Steel 316 are listed below.

Table of Contents

304 Grade Stainless Steel

Stainless steel 304 is the most ordered stainless steel in the world. It is an austenitic stainless steel containing sulfur, carbon, manganese, silicon, and 8 to 10.5 percent nickel. It also contains 18 to 20 percent chromium. Because of these components, SS 304 is highly resistant to heat and corrosion and can be used in a variety of industrial and commercial environments.

Because of its properties and characteristics, SS 304 is the most popular grade of stainless steel. It is used in a wide range of applications. It works well in a variety of environments and has a beautiful appearance due to its strong resistance to rust. It is also the best choice for CNC machining and sheet metal production as it can be machined and welded. A lot of people like the way it looks, as evidenced by the fact that it is used to make parts for skyscrapers and high-rise buildings.

304 Grade Stainless Steel Parts-Yonglihao Machinery

316 Grade Stainless Steel

316 stainless steel, also known as 316 SS, is also an austenitic steel. It contains no more than 0.08% carbon and contains 10% nickel, 16% chromium, and 2% to 3% molybdenum. As an austenitic steel, it can withstand a lot of heat, can be machined or welded, and has high tensile strength. The additional 2% molybdenum makes it more resistant to corrosion in salt water and groundwater, which contain high levels of chlorides.

Stainless steel 316 also has some advantages over stainless steel 304. With more nickel and an additional 2% molybdenum, 316 stainless steel is more resistant to corrosion than 304 stainless steel. It can withstand acidic, alkaline, and chloride environments. It is also flexible, machinable, and weldable, which makes it another excellent material for rapid prototyping. SS 316 is also often used in the medical field because its hard surface prevents bacteria from sticking to it and surviving.

Differences between 304 and 316 Stainless Steel

304 and 316 stainless steel have different properties. To choose the right grade of stainless steel, you need to understand the differences. To select the right stainless steel for your project, note the following seven key differences.

Differences in Chemical Composition

The main difference between 304 and 316 stainless steel is their chemical composition. The following are the differences in the chemical composition of these two stainless steels.

  • 304 stainless steel consists of 18% chromium and 8% nickel.
  • 316 stainless steel consists of 16% chromium, 10% nickel, and 2% molybdenum.

Compared to 304 stainless steel, 316 stainless steel has less chromium and more nickel in its chemical composition. Unlike 304 stainless steel, it also contains 2% molybdenum. Because of these differences, the two grades have different properties and can be used for different applications.

Differences in Mechanical Properties

When selecting the type of stainless steel to be used, look for tensile strength, yield strength, compressive strength, and shear modulus. The following are some ways of comparing stainless steels 304 and 316 based on their different qualities.

Tensile Strength

Tensile strength is the force required to pull a piece of material apart. Tensile strength also shows how long the material will stretch before it breaks.

If the thickness of 304 stainless steel is 8 mm, the tensile strength is 520-720 MPa. If the width is 8-75 mm, the tensile strength is 540-750 MPa. If the thickness of the stainless steel is 160 mm, the tensile strength is 500-700 MPa.

If 316 stainless steel is 8 mm thick, it can withstand a tensile force of 530 to 680 MPa. If the thickness is 8 to 75 mm, it can withstand a tensile force of 520 to 670 MPa. If the thickness is 160 mm, it can withstand tensile forces of 500 to 700 MPa.

Yield Strength

The yield strength of a metal tells you how much force can be applied before it changes shape permanently. 316 stainless steel has a yield strength of 290 MPa, and 304 stainless steel has a yield strength of 215 MPa. Therefore, the yield strength of stainless steel 316 is stronger than that of stainless steel 304. This means that SS 316 is more suitable than SS 304 for manufacturing items that are subjected to greater stress.

Hardness

A material’s resistance to bending, abrasion, penetration, and indentation depends on its hardness. 316 stainless steel has a hardness of 79 Rockwell hardness B, while 304 stainless steel has a hardness of 70 Rockwell hardness B. Though the difference is not significant, 316 stainless steel is better suited for items with higher friction.

Modulus of Elasticity

The modulus of elasticity shows the relationship between stress and strain when a metal is deformed. 316 Stainless Steel has a modulus of elasticity of 164 GPa while 304 Stainless Steel has a modulus of elasticity of 193-200 GPa. this proves that SS 304 can handle deformation better.

Differences in Corrosion Resistance

Stainless steel 316 has superior corrosion resistance than stainless steel 304. Like other types of stainless steel, SS 304 will not rust. On the other hand, the 2% molybdenum contained in SS 316 makes it more resistant to chlorine and has a better resistance to acids and alkalis.

As a result, SS 316 is better suited for products used in salt water or other rust-prone environments. Of course, SS 304 is still highly resistant to corrosion.

Differences in Temperature Resistance

Temperature resistance is an important characteristic to consider when products are used in high-temperature areas. Stainless Steel 304 is superior to Stainless Steel 316 in terms of temperature resistance. Its melting point is 50 to 100 degrees Fahrenheit higher than 316 stainless steel.

SS 304 can withstand high temperatures well, but may rust if used continuously at temperatures from 425 to 860 °C (797 to 1580 °F).

Above 843 °C (1550 °F) and below 454 °C (850 °F), SS 316 is a metal with good heat resistance.

Durability

Durability refers to the strength of a material and its ability to withstand damage from abrasion, corrosion, stress, deformation, and heat. 316 and 304 grades are both durable, which means they can be used in rigorous production structures. SS 316 has a slight advantage, however, because of its better corrosion resistance.

Weldability and Formability

The weldability of stainless steel depends on the amount of carbon content. Because the higher the carbon content, the less weldable it is, SS 304 and SS 316 both have a carbon content of 0.08%, but some of their other components are slightly different. Because they are slightly different materials, their weldability is slightly different. However, both types of stainless steel can be easily welded by arc welding.

Price Differences

When it comes to price, SS304 is cheaper than SS316. SS 316 is 75% more expensive than SS 304 because it has additional metal elements. This makes the production process of stainless steel 316 more complicated. The extra ingredients also make it more resistant to rust and corrosion, which increases its value.

Common Applications for 304 and 316 Stainless Steels

Stainless steel is used in many applications due to its ability to resist corrosion. On the other hand, different grades of stainless steel can increase corrosion resistance or improve other qualities such as toughness, tensile strength, and service life. Since 304 and 316 stainless steel are different types, they can be used for many different purposes. Some of the common uses of stainless steel are listed below.

Aerospace Industry

Many parts used in the aerospace industry are made from stainless steel. For example, CNC machining can use stainless steel to manufacture aerospace parts. This is due to the fact that stainless steel is lightweight, has high tensile strength, does not rust, and has a long service life. Because of these properties, both SS 304 and 316 stainless steels can be used to manufacture aircraft parts such as actuators, fasteners, landing gear parts, etc.

Medical Equipment

Medical equipment needs to be resistant to rust, and corrosion, easy cleaning, and sterilization. Both stainless steels have these properties. Therefore they are both suitable for making medical tools and equipment such as scalpels and implants.

Household Tools

Both stainless steels can be used to make kitchen tools such as knives and forks. They have good mechanical properties, durability, heat resistance, and aesthetics.

Food and Beverage

Stainless steels SS 304 and 316 are strong and durable and can be used to make food and beverage containers. What’s more, they don’t rust because they don’t react with acids and alkalis. As a result, they are suitable for many different foods, whether or not they contain light salt. They have a smooth surface that is easy to clean and will not harbor bacteria.

Which Is Better for Your Project

After learning about the pros, cons, and uses of the two types of stainless steel, 304 and 316, you may be wondering which one is better. As you may have guessed, there isn’t just one answer. However, we will answer some questions below to help you pick the best stainless steel for your job.

Where Will the Product be Used?

Either of the two stainless steels can be used where corrosion is a problem. However, 316 stainless steel is better in places that are acidic, salty, or full of chlorides. This is because it contains 2% molybdenum, which provides a high level of rust resistance.

What Is the Operating Temperature?

Temperature causes stainless steel to corrode. Therefore, 316 stainless steel works better when the temperature at the point of operation is between 454 °F and 843 °F.

What Is Your Budget?

If the above properties are not required, it is better to choose 304 stainless steel rather than 316 stainless steel. The cost of 304 stainless steel is approximately 25% less than 316 stainless steel.

Conclusion

The debate between SS304 and SS316 is a long one. To choose the right product, you need to understand its characteristics, benefits, and uses. This article on the differences between these two stainless steels can help you choose the right stainless steel grade for you.

If you are still hesitant to choose the right product. It’s best to hire a trusted rapid prototyping service company to help you choose the right material. That’s where Yonglihao Machinery comes in.

Yonglihao Machinery is one of the best and most professional rapid prototyping service companies. We offer a wide range of services including CNC machining, sheet metal fabrication, injection molding, 3D printing, and more. We offer specialized stainless steel services and can help you manufacture high-quality steel products for a wide range of fields such as aerospace, medical devices, and more.

We can also provide you with instant quotes to make the manufacturing process even better. Are you unsure how to choose the right material? We can help you if you contact us.

FAQ

It is not easy to answer this question. There are many different grades of stainless steel, each with specific uses. Therefore, it is not the case that one grade of stainless steel is better than another. The right stainless steel for you depends on your project and the mechanical, chemical, and other properties you require.

Because 316 stainless steel contains nickel, molybdenum, and chromium, it will not rust or corrode. Because of this, it can be used in areas where rust and weathering are common.

The price difference between 304 and 316 stainless steel is due to their chemical composition. The cost of buying 316 stainless steel is higher than 304 stainless steel. The addition of 2% molybdenum and more nickel makes the product more expensive to manufacture. This makes this grade more valuable because it is less likely to rust.

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