Stainless steels are versatile materials used in many applications. It is famous for its strength, durability, and corrosion and oxidation resistance. However, it serves many industries, including construction, automotive, aerospace, chemical, and food processing. In the case of applications, stainless steel can be of different types. SS304 and SS316 are the two most common stainless steel in these industries. Therefore, 304 vs 316 stainless steel is an important topic to understand the importance of these two materials.
SS304 and SS316 are both famous for their physical and chemical properties. Both of them share many similarities. Although, some critical differences can make one a better choice than another in specific applications. In this case, SS316 provides better performance than 304 steel. Yet, considering the budget, SS304 is an excellent choice. Therefore, selecting between these elements depends on the specific application requirements.
This article will examine the key differences between 304 and 316 stainless steel. We will review their chemical composition, corrosion resistance, strength, durability, and cost. However, you can select the right element for your application by understanding these differences. And the end of this article, you can also find a summary table explaining all these critical differences in short. Therefore, sit tight and read the following key points patiently.
304 vs 316 Stainless steel
Stainless steel is a highly versatile and durable material. It is popular in various industries, from construction to medical applications. We know that not all stainless steel is created equal. Although, both 304 and 316 stainless steel come with some similar properties. Yet, they differ in chemical composition, strength, and other resistance abilities.
The following sub-sections discuss some critical factors of different stainless steel types. These key factors typically differentiate the properties of 304 vs 316 stainless steel. Understanding these differences helps in selecting the correct type for your target application. As a result, you can ensure the best possible outcome from your project.
Chemical composition: 304 steel vs 316 steel
The chemical composition of SS304 and SS316 is the primary factor that sets them apart. In this case, both steel types contain a similar amount of chromium and nickel. The presence of these two elements gives them the characteristics of corrosion resistance. Because of this physical property, stainless steels are widely popular in many applications.
SS304 typically contains 18% of chromium and 8% nickel content. On the other hand, SS316 contains 16% chromium, 10% nickel, and 2% molybdenum content. However, the presence of molybdenum gives SS316 more resistance to pitting and crevice corrosion. As a result, they are famous for marine applications where saltwater and other harsh conditions are common threats.
Corrosion resistance: 304 vs 316 Stainless steel
Corrosion resistance is another crucial consideration when selecting between the two stainless steel. We know that both 304 and 316 stainless steel are highly corrosion-resistant. However, SS304 and SS316 only differ in their ability to withstand certain types of corrosion. They also differ in their suitability for different environments.
304 steel is generally resistant to most forms of corrosion. It can resist rust, tarnishing, and pitting. Although, it may be susceptible to specific environments, such as high chloride levels or exposure to certain acids. On the other hand, 316 stainless steel is almost resistant to all forms of corrosion. In this case, the factor contributing to the superior corrosion resistance of SS316 is its higher molybdenum content.
Strength and durability: 304 steel vs 316 steel
SS304 and SS316 are both strong and durable. They only differ in the mechanical properties that make them suitable for unique applications. However, SS304 is a low-carbon steel that has good strength and toughness. On the other hand, SS316 is higher-carbon steel. Both 304 and 316 stainless steel have a yield strength of 200 to 275 MPa (30000 psi to 40000 psi) and a tensile strength of 500 – 700 Mpa (75000 psi to 95000 psi).
316 stainless steel is more durable than 304 stainless steel. In addition, 316 stainless steel can withstand higher levels of stress and strain without deforming or cracking. As a result, SS316 is more prevalent in applications that require high strength and durability. Marine equipment, chemical processing, and medical implants are some noteworthy examples.
Heat Resistance: 304 vs 316 Stainless steel
Both 304 and 316 stainless steel come with good heat resistance ability. Like other factors, their performance can vary depending on the specific application condition. SS304 has a maximum operating temperature of around 870°C (1600°F). On the other hand, SS316 has a maximum operating temperature of about 1399°C (2550°F). 304 stainless steel is unsuitable for continuous use at temperatures above 800°C (1472°F). In these applications, 316 steel can be the right choice for use at continuously high temperatures.
Thermal expansion is another essential factor to consider. It affects the dimensional stability of the material. However, the composition of the stainless steel may also affect the heat resistance property. In this case, higher carbon and alloying elements can improve this ability.
Applications
304 steel is a versatile and cost-effective material suitable for many applications. Contrariwise, 316 steel is famous for its superior corrosion resistance. In addition, 316 steel is also famous for its ability to work in harsh environments. Therefore, the choice of material depends on the specific requirements of the applications. The applications’ environment, compatibility, and performance under different conditions are typical factors considered.
Applications of 304 stainless steel:
- Food processing equipment, such as tanks, pipes, and utensils
- Kitchen appliances, such as sinks, countertops, and range hoods
- Architectural applications, such as elevator interiors and handrails
- Automotive parts, such as exhaust systems and trim
- Chemical processing equipment, such as storage tanks and pipes
- HVAC equipment, such as heat exchangers
- Brewery and wine-making equipment, such as fermentation tanks and pipes
- Textile processing equipment, such as dyeing and finishing machinery
- Oil and gas industry
- Water treatment and purification systems
Application of 316 stainless steel:
- Marine and coastal applications, such as boat hardware and seawater equipment
- Medical devices and implants, such as surgical instruments and prosthetics
- Food and beverage applications that require high purity
- Aerospace components, such as engine parts and landing gear
- Petrochemical equipment, such as HVAC systems and pressure vessels
- Electronics industry
- Nuclear industry equipment, such as fuel storage and handling systems
Budget
The overall cost of stainless steel depends on various factors. Alloy, the number of metals, and the complexity of the fabrication process handle the overall cost of stainless steel. Generally, SS304 is less expensive than 316 stainless steel.
Chemical composition is the primary reason for the varying costs of stainless steel. 316 stainless steel is more expensive than 304 stainless steel because of its molybdenum contents. However, molybdenum is a costly metal. It typically enhances the corrosion resistance of stainless steel. Besides, the cost of stainless steel also depends on its availability. 304 stainless steel is widely available and commonly used. Therefore, 304 is more affordable and easy to find.
Which is better, 304 or 316 stainless steel?
When choosing between 304 and 316 stainless steel, the selection mainly depends on the specific application. The selected material must meet the desired properties required for the end product. Regarding corrosion and heat resistance, 316 is superior to 304 stainless steel. As a result, 316 is highly suitable for harsh environments, such as marine or chemical processing applications. Concerning strength, 316 is also superior to 304 stainless steel. The presence of molybdenum enhances its resistance to pitting and crevice corrosion.
However, 304 stainless steel is an affordable and widely available material. As a result, it is suitable for less demanding applications.
Summary
Selecting between 304 vs 316 stainless steel requires consideration of many factors. Sometimes, considering other factors is more critical than just cost. The specific application requirements should suit the different properties of these two elements. We have learned that SS316 is a better option for every property we discussed above. However, if your application suits SS304, you can ensure a high-quality application cost-effectively. Here is the summary of the differences between SS304 and SS316.
| Property | 304 Stainless steel | 316 Stainless steel |
| Chemical Composition | Chromium – 18%, nickel – 8% | Chromium – 16%, Nickel – 10%, Molybdenum – 2% |
| Corrosion Resistance | Good general but susceptible to chloride-induces pitting and crevice corrosion | SS316 is excellent in corrosion resistance in general and chloride-induced. It is also resistant to stress corrosion cracking. |
| Strength and durability | Good tensile and yield strength, lower than SS316 | SS316 comes with higher tensile and yield strength than SS304. It is also better for fatigue resistance. |
| Heat Resistance Capability | SS304 has good oxidation resistance up to 870°C (1600°F), less resistant to thermal shock | SS316 has a higher oxidation resistance capability than SS304, up to 925°C (1700°F). It is also more resistant to thermal shock. |
| Applications | Equipment used in food processing, chemical processing, and architectural applications | Marine, medical implants, chemical processing, and food processes |
| Cost | Less expensive than SS316 | More expensive |
Above all, consulting with a knowledgeable materials engineer or supplier is always better. It helps in ensuring the best possible outcomes. However, you can also consult with our customer service team. Dawang Casting keeps a group of materials experts willing to answer your questions.
