Sheet metal assemblies often require joints to function properly. The design of these joints depends on various factors such as material, pressure, thickness, and intended use.
PEKO offers contract assembly services for sheet metal components, providing complete assemblies for a wide range of industries.
Below are 5 common types of fabricated sheet metal joints to explore:
Lap Joints
One type of lap joint involves overlapping two edges in a specific way.
Plain Lap Joint
A plain lap joint does not require any fabrication and can be as simple as two edges offset by their thickness and length.
Flush Lap Joint
A flush lap joint consists of one edge sliding under the other piece on the same plane.
Standing Seam Joint
A standing seam joint requires forming both edges, with one edge fitting over the other and being joined with rivets or welds.
This type of joint is ideal for larger applications like plenums and skins.
Standing seam joints are known for their durability and weather resistance, making them suitable for outdoor applications. The raised seams provide added strength and help prevent water infiltration, making them popular for roofing and cladding systems.
Groove Seam Joint
A grooved seam combines elements of a flush lap joint and open hems, allowing for quick assembly and welding.
Corner Joints
Raw and Flange Corner Joint
This joint involves joining flat stock to a 90-degree bend, which is suitable for heavier gauge materials.
Flange and Flange Corner Joint
Creating a flange joint includes forming a flange on each piece and joining them to create flush outside corners.
Butt Joint
A butt joint is a simple method of joining two pieces of material at a right angle without any overlapping. It is commonly used in woodworking and metalworking.
Miter Joint
A miter joint is formed by cutting two pieces of material at an angle, usually 45 degrees, and joining them to form a corner. This type of joint is often used in picture frames and woodworking projects.
Double Corner Seam
The double corner seam incorporates aspects of corner and grooved seams, making it ideal for compound curves.
These 5 sheet metal joints are just a few examples of the many options available for fabrication.
Discover alternative techniques for joining sheet metal without fasteners, including clinching, hemming, welding, brazing, soldering, and adhesive bonding.
Here are some ways to join sheet metal without using traditional fasteners:
| Technique | Advantages | Disadvantages | Materials Compatibility | Uses |
|---|---|---|---|---|
| Clinching | Advantages of Clinching | Drawbacks of Using Clinching | Materials Suitable for Clinching | Practical Applications of Clinching |
| Hemming | Advantages of hemming. | Disadvantages of hemming. | Materials that can be hemmed. | Uses of hemming. |
| Welding | Advantages of welding. | Disadvantages of welding. | Materials that can be welded. | Various welding applications. |
| Brazing | Advantages of Brazing | Disadvantages of Brazing | Materials Suitable for Brazing | Uses and Benefits of Brazing |
| Soldering | Advantages of using soldering. | Disadvantages of soldering. | Materials that can be soldered. | Various uses of soldering. |
| Adhesives | Advantages of using adhesives | Disadvantages associated with adhesives | Materials that work well with adhesives | Various uses of adhesives |
Ways to join sheet metal without fasteners
Connect sheet metal using mechanical methods, welding, thermal processes, or adhesives.
Clinching
Clinching alters materials to create a strong bond that is suitable for a variety of applications and materials.
Multiple sheets of different metals can be united through clinching, making it adaptable for diverse materials and uses.
When selecting joining techniques for sheet metal, it’s crucial to comprehend the pros and cons of each choice.
Hemming
Hemming includes folding the edge of a sheet over itself or another sheet to produce a smooth, curved edge commonly found in automotive and appliance production.
Welding
Welding is highly efficient in creating sturdy joints, with methods such as MIG, TIG, spot welding, and laser welding offering various applications. Welding generates joints that are exceptionally strong, on par with the material itself.
Brazing
Brazing utilizes a filler metal with a lower melting point than the base metals to form a strong, leak-proof joint. While not as robust as welding, the lower melting point decreases the risk of thermal distortion.
Soldering
Soldering involves lower temperatures and is commonly used for connecting thin materials, particularly in electronics. It is easier to automate for high-volume production and can join dissimilar metals, but is limited to thin materials and smaller joints.
Adhesives
Adhesives offer a versatile approach to joining sheet metal, establishing strong connections by evenly distributing the load across the joint. However, thorough surface preparation is essential for optimal bonding.
Joining of Metals: Method # 6. Adhesive Bonding:
Adhesive bonding is a method that uses adhesives or glues to join metals together. It is a versatile method that can be used for joining a wide range of materials, including metals, plastics, and composites. Adhesive bonding provides a strong and durable bond, as well as the ability to join dissimilar materials.
Advantages of Adhesive Bonding:
– Adhesive bonding allows for joining of materials with different properties, such as thermal expansion coefficients or electrical conductivity
– It can distribute stress evenly across the joint, reducing the likelihood of stress concentrations
– Adhesive bonding can provide corrosion resistance and seal out moisture, preventing rust or degradation of the joint
Types of Adhesives used for Metal Bonding:
– Epoxy adhesives are commonly used for bonding metal surfaces together. They provide high strength and durability, as well as resistance to chemicals and environmental factors
– Cyanoacrylate adhesives, also known as super glue, are fast-setting adhesives that are suitable for bonding small metal components quickly
– Polyurethane adhesives offer flexibility and impact resistance, making them ideal for applications where the joint may experience movement or vibration
When using adhesive bonding for joining metals, it is important to properly prepare the surfaces to be bonded by cleaning and roughening them to ensure good adhesion. Additionally, proper curing and clamping of the bond are essential for achieving optimal strength.