Main 6 Ways to Join Metal Parts in Manufacturing

In this blog post, we'll explore six main methods used in metal fabrication - welding, adhesive bonding, mechanical fastening, brazing, soldering, and riveting - along with their advantages and disadvantages.

So if you're keen on discovering which technique suits your project best or want to expand your knowledge about these fascinating processes, keep reading!

The Six Main Methods For Joining Metal Parts In Manufacturing

Welding: Strong But May Deform The Metal

It involves melting two pieces of metal together using heat and a filler material.

This process creates an extremely strong bond between the two pieces but can also deform or change the shape of the joined materials.

Welding is excellent for projects where strength is crucial, like building structures or car components.

However, it may not be suitable for projects that require precision or intricate details because it can alter the shape of the metal during the joining process.

For example, there might be better options than welding if you work on delicate jewelry or small electronic parts, which could ruin their appearance and functionality.

Adhesive Bonding: Versatile But May Not Be Suitable For High-stress Environments

Adhesive bonding is a popular method of joining metal parts, especially those with irregular shapes or contours.

It involves adhesives that are applied to the surfaces to be bonded and capable of holding them together when cured. Adhesive bonding is versatile and can be used for various metals, including aluminum, steel, and titanium.

However, it may not be suitable for high-stress environments as the strength of the bond may not hold up against constant heavy loads.

One industry where adhesive bonding has proven very useful is aircraft manufacturing. The lightweight properties of adhesives make them an ideal option for joining small components such as brackets and clips that need to withstand stress from vibration or temperature variations but do not bear significant weight.

Additionally, automotive manufacturers use adhesive joints in their production process because they provide a clean finish without disrupting the appearance and design aesthetics.

Mechanical Fastening: Easy To Use But May Weaken The Metal

Mechanical fastening is one of the easiest ways to join metal parts together. This method uses screws, bolts, nuts, and other mechanical fasteners to secure the components. They are easy to install and can be used with various metals and materials.

However, while mechanical fastening may be convenient, it can weaken the metal over time. In addition, using too many fasteners or overtightening them can cause stress points that could eventually lead to cracks or fractures.

Therefore, it's essential to carefully consider the strength requirements for your project before choosing this method of joining metal parts together. In some cases, welding or brazing may be a better choice for ensuring a stronger bond that will last longer without compromising the material's structural integrity.

Brazing: Strong And Effective For High-stress Environments But May Require More Time And Equipment

I've always been impressed with brazing as a joining method in metal fabrication because of its strength and effectiveness in high-stress environments. It involves melting a filler material into the joint and solidifying it to fuse the metal parts.

The resulting bond is incredibly strong and can withstand extreme temperatures and pressure. However, it does require more time and equipment than some other methods.

Brazing is commonly used in aerospace, automotive, and construction industries, where components must withstand harsh conditions.

One example of brazing's effectiveness is in heat exchangers for cooling systems, where it helps ensure that metals remain fused even under varying thermal loads.

Brazed joints also have excellent ductility characteristics that allow them to expand or contract without cracking or deforming.

Soldering: Great For Electrical Connections But Not Suitable For High-stress Environments

Soldering is excellent for creating strong, reliable electrical connections between metal parts.

The process involves heating a metal alloy -- typically made of lead and tin -- until it melts and adheres to the surface of the joined components. This creates a sturdy bond that can withstand both electrical current and vibrations.

However, it's important to note that soldering may not be suitable for high-stress environments where strength and durability are essential.

For example, if you're joining metal parts exposed to significant amounts of pressure or tension, you may need to consider other methods, such as welding or brazing instead.

In my experience working with electronics manufacturers, I've seen how soldering can be particularly useful in industries like telecommunications or consumer electronics, where precision and reliability are critical factors.

Riveting: Simple And Fast But May Not Be As Strong As Other Methods

It's simple to use and can be done quickly, making it perfect for high-volume production lines. However, it may not be stronger than other methods like welding or brazing.

One example of where riveting is commonly used is in the sheet metal industry for fastening panels together, such as those on the sides or roof of a car.

Another application could be in construction for joining thick beams together when welding isn't feasible due to limited space.

Factors To Consider When Joining Metal Parts In Manufacturing

Materials Type And Thickness

• Different welding techniques work better for certain materials. For example, gas tungsten arc welding (GTAW or TIG) is often used for thin materials like stainless steel, while gas metal arc welding (GMAW or MIG) is better suited for thicker materials.
• Adhesive bonding can be used with various materials, including metals, plastics, and ceramics. However, the strength of the bond may vary depending on the material being used.
• Riveting is commonly used with sheet metal and can be effective with thin and thick materials.
• Mechanical fastening methods like screws and bolts can work well with various materials but may not be suitable for thin sheets or fragile parts.

Component Shape And Size

If you're working with sheet metal fabrication and need to join two thin pieces, adhesive bonding may be your go-to option because it can easily bond flat surfaces without leaving any visible signs of a joint.

On the other hand, mechanical fastening techniques like screws or clinching joints may be better suited for larger components that require more strength and stability.

Joining methods like welding can also work well for heavier or irregularly shaped pieces since they can fuse multiple parts into one cohesive unit.

Strength Requirements

Tensile strength

This is the maximum stress a material can withstand before breaking under tension. Welding and brazing are known for their high tensile strength.

Shear strength

The maximum stress a material can withstand before breaking under a perpendicular force. Mechanical fastening and adhesive bonding are excellent options for achieving high shear strength.

Résistance à la fatigue

If your product will be subject to repeated stress cycles, choosing a joining method that will resist cracking or deformation over time is essential. Welding and brazing perform well in this area.

Résistance à la corrosion

Depending on your product's environment, you may need to choose a joining method that resists rust or other forms of corrosion. Adhesive bonding is known for its ability to seal out moisture and prevent corrosion.

Résistance à la température

Some joining methods may weaken or fail at high temperatures, so choose an option that can withstand the conditions your product will experience.

Aesthetics

If appearance is important, you'll want to choose a joining method that produces clean, uniform seams or joints. Adhesive bonding and welding are excellent options for achieving a smooth, seamless look.

Production Volume And Cost

Mechanical fastening or adhesive bonding is often cheaper for large production quantities than welding. Welding involves skilled labor, specialized equipment, and time-consuming setup.

In contrast, techniques like brazing or soldering are more suitable for small production quantities as they require less equipment and have shorter setup times.

However, these methods incur higher material costs due to the use of filler materials.

Environment And Location Of The Final Product

Résistance à la corrosion

If the final product is exposed to harsh environments or corrosive substances, choosing a joining method that will provide sufficient corrosion resistance is essential.

Temperature extremes

Will your product be subjected to extreme temperatures? If so, consider joining methods that can withstand these conditions without losing strength or degrading.

Vibration/movement

Will your product be subject to vibration or movement? In this case, you'll want to choose a joining method that can withstand repeated stress without loosening or weakening.

Aesthetic considerations

For products where appearance is essential, like jewelry or decorative metalwork, consider using joining methods that result in clean seams and minimal visible distortion.

Size limitations

Depending on the size of your final product, specific joining methods may need to be more practical and feasible. Ensure that the way you choose is appropriate for the size and shape of your components.

Location of manufacture

Where will your final product be manufactured? If it is produced in an area with limited access to specialized equipment or trained personnel, more straightforward joining methods like riveting or mechanical fastening make more sense than complex techniques like welding or brazing.

Applications And Industries Of Different Joining Methods

Welding For Building Structures And Car Components

Welding is vital for constructing buildings and cars, enabling the joining of large metal pieces into complex structures with minimal distortion.

In the automotive industry, it is essential for assembling engine blocks and exhaust systems, contributing to noise reduction and improved fuel efficiency.

Heavy machines like cranes and excavators also rely on quality welding for durability and stability.

Adhesive Bonding For Aircraft And Aerospace Industries

Adhesive bonding is vital in aerospace for lightweight, strong bonds between different materials.

It enables flexibility in design, allowing engineers to join dissimilar materials and reduce weight compared to traditional methods.

However, it may not be suitable for high-stress environments like flight or extreme temperatures.

Mechanical Fastening For Automotive And Heavy Machinery Industries

Mechanical fastening includes methods like clinching joints, where a tool presses metal sheets until they deform and connect, and screw joints, involving drilling holes and securing them with screws.

While it's fast and cost-effective compared to welding or brazing, it may weaken metal over time due to stress concentrations around joints.

Brazing And Soldering For Jewelry And Electronics

Brazing melts a metal filler to create a strong bond between joined metals, which is ideal for high-stress environments.

Soldering, using lower temperatures, melts a softer metal alloy to create electrical connections by flowing into gaps between metals.

It is commonly used in electronic devices for reliable joints without damaging delicate components.

Riveting For Sheet Metal And Construction Industries

Riveting is commonly used in construction projects such as bridges, roofs, and industrial buildings.

It's also frequently used in automotive and aerospace manufacturing for attaching sheet metal components where strength requirements are not critical.

Conclusion: Joining Metal Parts In Manufacturing

And there you have it - the main six ways to join metal parts in manufacturing!

Each method has advantages and disadvantages, so it's essential to consider all factors before selecting the best technique for your project.

Whether you're working with sheet metal or building structures, understanding these joining methods can help improve the quality and durability of your products.

From spot and seam welding to adhesive bonding and riveting methods, various options can cater to different materials, shapes, sizes, strengths requirements, production volume, and costs.

When choosing a joining method, it is also essential to consider the specific application or industry.

By exploring different metalworking techniques such as mechanical fastening, brazing, and soldering, among others - manufacturers can unlock their full potential with efficient assembly techniques that ultimately lead to superior final products.

If you need help determining which method will best suit your project needs, contact our expert team, as we can guide you through the selection process while considering the important factors mentioned in this article.