Sheet Metal Fabrication Techniques

Posted by CNC Machining Hong Kong on October 24, 2019 3:57 am | Leave a Comment

Sheet metal fabrication is a process of creating volume from flat sheet material for limitless application. It usually involves cutting, forming, rolling, or pressing the sheet metal using special tools to design specifications so that they can be assembled with other components to create finished products. Some of the common industrial and commercial items produced by sheet metal fabrication include:

Electronics housings
Hand tools (shovels, rakes, post hole diggers)
Cans
Automotive body panels
Mounting bracketry
Construction Equipment
Exercise equipment

Depending on the requirements of the design and application, there are numerous sheet metal fabrication techniques available, including forming, stamping, punching, rolling, laser cutting, and shearing.

SHEET METAL FORMING

Sheet metal forming is an effective method for producing sheet metal parts in complex three-dimensional shapes using minimal material. The desired shape is achieved through plastic deformation, without the need for machining.

There are two major categories of sheet metal forming: hot and cold forming. Hot forming is when the raw material is manipulated into shape while in a partially liquefied state, this can be achieved through localized heat from a torch, heated tooling, or specialized ovens. This becomes more necessary with thicker materials and more complex shapes. Cold forming is when metal is formed at/near room temperature through use of high tonnage presses and standardized tooling. This is more applicable to thinner materials and less organic shapes.

As is the case in many industries, robotics have been applied to sheet metal forming as a way to increase overall productivity but also to cut down on some of the upfront tooling costs seen in other fabrication methods such as stamping.

SHEET METAL STAMPING

Sheet metal stamping is a forming process that creates three-dimensional shapes through permanent deformation. It employs a mechanical or hydraulic press and a custom designed punch and die set to create stamped parts and is suitable for producing large quantities of high precision metal parts at low costs. However, initial set up costs are often very high and tooling life and maintenance can often lead to hidden costs.

Sheet metal stamping is often used to create metal parts used in the automotive, household appliances, and medical industries.

SHEET METAL PUNCHING

Similar to stamping, sheet metal punching uses heavy machinery and a punch and die assembly to put holes or indents into pieces of sheet metal. As the machine forces the punch component through the metal, it causes the metal underneath the punch to be separated from the rest of the sheet. The cut metal is then collected in a container and saved for future use or recycling. Punching was the primary method for CNC sheet metal cutting for many years before the development of water and laser cutting tools and still specializes in high speed hole application and low-consumable production costs.

It can be used to create specific shapes and designs in finished parts and components, such as vent openings.

SHEET METAL ROLLING

Sheet metal rolling passes the metal through three rollers to shorten one face of the material and elongate the opposite face causing a progressive curvature in the sheet. This can be done to create complete tubes or to roll to a specific profile. More advanced rolling machines are able to form extremely complex tangential profiles with precision and repeatability.

Some products that can be made using this process include lock-seam pipes, welded pipes, and open-butt-joint pipes.

SHEET METAL LASER CUTTING

Laser cutting directs a high-powered laser through optical components to cut sheet metal into custom shapes and designs for industrial and commercial applications. Compared to similar processes, such as plasma cutting, it is more precise and uses less energy, and is suitable for cutting and engraving a variety of metals, including aluminum, copper, and steel.

For thicker material you may need to utilize water jet cutting as most laser cutters are not suitable above 1” thick material.

SHEET METAL SHEARING

Shearing employs a set of upper and lower straight-edge blades to cut flat metal stock—such as aluminum, brass, bronze, and stainless steel—into separate pieces. The blades are typically offset from each other with the upper blade angled to facilitate the cutting operation.

This process is usually used to cut sheet metal into smaller sizes to prepare it for further processing, rapid prototyping of very simple parts, or commonly in A/C duct manufacturing.

CONCLUSION

There are many different techniques used in sheet metal fabrication, including stamping, punching, rolling, and shearing. Each technique has a distinct purpose and is used to create different shapes and components, which often require additional finishing and treatment processes following fabrication.

CNC Machining Hong Kong Inc. has been committed to providing customers with precision sheet metal fabrication services since 1969. Our team has the experience and expertise needed to get your job done properly and promptly. These qualities, combined with some of the most advanced metal fabrication equipment around, allow us to provide you with exceptional quality at low prices.