Metal gaskets are used to seal the joints between two surfaces and ensure that leaks do not occur in industrial equipment. Different industries utilize gaskets for a variety of uses, including engines in vehicles, pipelines that transport fluids or gases, and many others all over the world. When a gasket fails, the consequences can be severe. Whether the gasket holds together or fails depends on the metal gasket material. High temperatures can cause rubber gaskets to fail in a matter of hours, while aggressive chemicals can corrode incompatible metals just as quickly. This guide includes seven metals that are frequently found in gasket manufacturing. 

Metal Gasket Materials

Metal gaskets are available in several materials, and each metal gasket material behaves differently in given conditions. The seven materials mentioned here are the most common in industrial applications.

Carbon Steel 

Key Characteristics:

• Economical and readily available  
• Reasonable tensile strength to moderate pressures  
• Will corrode readily in the presence of moisture  
• Approximately 400°C temperature limit  
• Low corrosion resistance 

Applications: 

Carbon steel gaskets are used in oil and gas pipelines. HVAC systems and low-pressure steam lines use carbon steel gaskets. The automotive industry uses them in non-mission-critical components.

304 Stainless Steel

Key Characteristics:

• More corrosion-resistant than carbon steel  
• Has chromium and nickel, which provide protection from oxidation  
• Temperature rating up to 800°C  
• Non-magnetic and easy to work with during fabrication  
• Safe for food-grade use 

Applications: 

304 stainless steel is used in food processing equipment. Chemical processing plants that handle mild acids and bases utilize 304 stainless gaskets. Water treatment facilities specify 304 stainless steel for clean water systems. 

316L Stainless Steel

Key Characteristics:

• Low carbon content for superior weldability  
• Molybdenum for resistance to chlorides and saltwater  
• Chemical resistance to aggressive chemicals  
• Temperature resistance to 900 degrees Celsius  
• High corrosion resistance 

Applications: 

316L is the stainless steel metal gasket material of choice for marine equipment and offshore oil platforms. It is resistant to corrosive environmental and physical exposure to saltwater. 316L is also the metal gasket material for chemical plants that deal with strong acids and corrosive materials. 

Inconel

Key Characteristics:

• Nickel-chromium superalloy designed for extreme environmental conditions  
• Maintains strength with temperatures over 1000 degrees Celsius.  
• Minimal thermal expansion  
• Oxidation-resistant and resistant to creep deformation  
• Very expensive, which is the reason Inconel is only used in extreme cases and high-performance needs 

Applications: 

In aerospace, Inconel gaskets are commonplace in jet engines designed for extreme temperatures. Petrochemical processing companies rely on Inconel gaskets for equipment that uses high-temperature reactions. Additionally, Inconel is used in some nuclear reactors because of the high radiation exposure in certain gaskets.  

Nickel 

Key Characteristics:

• Excellent performance characteristics under highly caustic environments  
• Strong performance in alkalis and reducing acids  
• Stable at temperatures up to 600 degrees Celsius  
• Excellent thermal conductivity  
• Poor resistance to oxidizing acids 

Applications: 

Nickel gaskets are considered standard for caustic soda production facilities, where caustic soda is present throughout the entire production system. The alkali processing plants rely on nickel gaskets for the requirement of reliable sealing. Additionally, food processing equipment utilizes nickel gaskets.

Copper 

Key Characteristics:

• Soft and easily worked 
• Effective thermal conductor 
• Temperature rating up to 250°C
• Acceptable for imperfect surfaces 
• Corrodes in acidic conditions

Applications: 

Copper gaskets are often used in automotive exhaust systems. Copper is ideal for heat exchangers due to its ability to transfer thermal energy. Copper gaskets or seals are also used in plumbing systems and for sealing applications.

Aluminium

Key Characteristics:

• Low weight and resistant to corrosion 
• Forms an oxide protective layer 
• Temperature rating up to 200°C
• More economical option 
• Reacts in strong acids or alkalis

Applications: 

Aluminum gaskets are used in electronics and semiconductor equipment, as they allow for electromagnetic shielding. The low weight of aluminum provides benefits to automotive components. 

Key Factors to Consider When Choosing Metal Gasket Material

Using the wrong metal gasket material can lead to wasted money and failure. These factors will help clarify which metal serves the purpose best. 

Temperature Range

Assess the maximum and minimum temperatures the gasket will be exposed to. Copper and aluminum will fail at temperatures above 250°C, while Inconel can withstand temperatures that exceed 1000°C. A metallic exhaust gasket material must sustain that high heat continuously.  

Chemical Exposure

Identify every chemical that will come into contact with the gasket. The effect of acids, bases, and salts will indicate which metal will not corrode. Carbon steel will corrode in a moist environment, but 316L will tolerate much more extreme chemical exposure

Pressure Requirements

With high-pressure systems, ensure the material will not yield. The strength of the stainless steels and Inconel makes them good candidates for extreme pressures, whereas copper is a softer metal that is used in lower-pressure applications. 

Surface Finish

If you have a rough surface finish, you will want a soft metal, such as copper, that can deform to the irregular surface. If your surface is smooth and flat, then you can effectively use harder metals, such as stainless steel.  

Corrosion Environment

Installations that are marine, chemical, and outdoor tend to have constant exposure to corrosion. 316L stainless steel and Inconel can resist corrosion better than carbon steel and aluminum.  

Industry Standards

There are industries that have specified industry standards for optimum performance and to meet safety requirements. For example, food processing applications will require food-safe or food-grade stainless steel.

TMNetch: Custom Metal Gaskets

TMNetch has been producing precision components, including metal gaskets, since 2011, using state-of-the-art photochemical etching technology. Their ISO 9001:2015 certified production facility offers unparalleled accuracy and quality.

Capabilities:

• Thicknesses from 0.01mm to 3.0mm
• Tolerance of ±0.03mm accuracy
• Size capabilities of up to 800mm × 1500mm
• Rapid turnaround with prototypes in 6 hours and production in 3 days

Materials Available:

Stainless steel (304, 316L), titanium, copper, nickel, brass, aluminum

Industries served include:

Aerospace, medical devices, electronics, fuel cells, semiconductors, automotive

Contact TMNetch for a custom metal gasket material solution that meets your exact needs.

FAQs About Metal Gasket Material

How to cut metal gasket material?

For thinner gaskets (less than 1mm), use plastic scissors or a rotary knife for soft metals. For thicker material, use shearing, laser cutting, or water-jet cutting for clean edges and accuracy.

What is the difference between metallic and non-metallic gaskets?

Metal gaskets perform better under high heat conditions and under extreme pressure. Non-metal gaskets are made of rubber and PTFE, which can seal under uneven surface conditions, cost less, and fail under high-heat conditions.

Are metal gaskets good?

Yes. Metal gaskets can perform in extreme applications up to 1000 degrees Celsius. They maintain pressure and resist chemicals better than the competition. 

Are metal gaskets better than rubber?

In high-heat and high-pressure conditions, metal gaskets will perform better than rubber gaskets. Rubber melts at 200 degrees Celsius, whereas metal can withstand much higher temperatures. Ultimately, it depends on your operating conditions and your budget.

Conclusion 

Selecting the appropriate metal gasket material can save you the trouble of potential gasket failures and reduce costs. Each metal has particular advantages. The initial factors to consider when selecting a material are temperature, chemical exposure, and pressure requirements. Making sure you have the right material for the application will provide you with a durable, long-term solution.