Sheet metal refers to metal plates with a thickness of 6mm or less. Sheet metal fabrication is a cold processing method that involves punching, bending, drawing, and forming. The thickness of sheet metal parts is consistent throughout the process.
Sheet metal processing is a highly efficient and cost-effective forming process that results in lightweight, strong, and electromagnetically shielded components.
It is widely used in industries such as automotive, electronics, and home appliances.
Mechanical engineers often use sheet metal parts when designing products made of this material.
The challenge lies in finding an economical and reliable way to join multiple sheet metal parts and in determining the best method for fastening sheet metal.
In this article, we will introduce the 6 types of sheet metal joining process that is often used in product design.
Sheet Metal Joining Fundamentals
Sheet metal joining is an essential process in the fabrication of various products and structures using sheet material. It involves connecting or attaching multiple sheets of metal together to create a desired shape or form. This process is commonly used in industries such as automotive, aerospace, construction, and appliance manufacturing.
There are several methods and techniques for joining sheet metal, each with its unique advantages and limitations. Some common methods include mechanical fastening, welding, adhesive bonding, and soldering. The choice of technique depends on factors such as the type of materials, the application, and the required joint strength.
Mechanical fastening is a popular method for joining sheet metal because it is quick and straightforward. It involves using hardware like screws, rivets, and bolts to connect the sheets, and can be easily disassembled if necessary. This method is suitable for a wide range of materials and thicknesses.
Welding involves heating the surfaces of the sheet metals to join them and forming a fusion bond. This method provides a robust and durable connection and is commonly used for applications that require high joint strength. Some common welding techniques for sheet metal include resistance spot welding, gas metal arc welding, and laser welding.
Adhesive bonding is a technique that employs special adhesives to bond the sheet metals. This method is advantageous for joining dissimilar materials and relatively thin sheets. Adhesive bonds also offer a smooth, aesthetic appearance and can redistribute stress across the joint.
Soldering is a process that uses a filler material, or solder, which is melted and applied to the joint surfaces to create a bond. Capillary action helps the solder flow and form a connection between the sheets. Soldering is often used for applications that cannot withstand high temperatures and require a low-stress bond.
Selecting the appropriate joining technique requires considering various factors such as material compatibility, joint strength requirements, and cost. Moreover, proper surface preparation, joint design, and process control are crucial to ensure a successful sheet metal joining process.
In conclusion, sheet metal joining plays a vital role in today’s industrial world. The industry continually develops new techniques and technologies to address the specific needs and challenges associated with joining sheet metals, ultimately enhancing the quality, durability, and performance of the final products.
Sheet Metal Joining Methods
1. Folding / Tab Joint
Sheet metal parts can be connected to each other by folding or bending tabs in the form of a buckle and a clamping slot. This method of assembly is simple and convenient, resulting in quick assembly.
However, it may not guarantee full positioning, and additional auxiliary positioning may be required.
2. Pulling Rivet
Riveting is carried out in the hole corresponding to the two parts, and a rivet gun is used to pull the rivet, expanding and deforming the outer rivet sleeve to fix the two parts together.
This connection is simple, convenient, and fast.
3. Self-clinching
Self-riveting is a method of using mutual deformation between sheet metal parts to achieve mutual fixation.
Although this method is simple, it is often used in applications where disassembly is not required.
4. Screw Joint / Fasteners
Self-tapping refers to the process of using self-tapping screws to create threads directly on a sheet metal piece, resulting in a tight fit and the ability to be disassembled.
5. Pressing Rivet
The press rivet process involves pressing a crimp nut or screw against the sheet metal, which can then be mated with a corresponding outer nut or screw.
6. Welding Joints
The main purpose of spot welding is to create a row of solder joints on two sheet metal parts.
This is achieved by melting the local sheet metal material at the welding head to complete the connection between the sheet metal parts.
In the above content, we introduced various sheet metal joining methods.
Finally, a table is used to summarize the advantages and disadvantages of each joining method.
Joining methods | Tools used | Pros | Cons |
---|---|---|---|
Folding / Tab Joints | none | 1. Low cost 2. Quick assembly | Can not completely limit all degrees of freedom, other fixing devices are needed |
Pulling Rivet | rivet gun | 1. Easy to operate, good fluidity 2. Self-positioning | 1. Need to pre-punch 2. The pull stud will have a bump 3. There is a limit to the use space of the rivet gun |
Self-clinching | dedicated mold | Self-guided, no positioning required | 1. Need to do the countersinking process 2. Do not disassemble 3. The yield rate is difficult to guarantee |
Screw Joint / Fasteners | screwdriver | Low cost, detachable | Limited number of disassembly |
Pressing Rivet | dedicated equipment | 1. Safe and reliable 2. Removable | Higher cost |
Welding Joints | spot welding machine | 1. Simple process 2. No pre-processing required | 1. Equipment complexity 2. Weak welding force, easy to remove welding 3. Unable to remove 4. Welding materials should match |
What are the types of jointing in sheetmetal