Archive: Oct 2019

Sheet Metal Fabrication Techniques

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.

Pro-Type Industries, 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.

Contact us today to learn more about how we can help you with your fabrication needs or request a quote.

CNC Milling Guide: Everything You Need to Know

Manufacturers use Computer Numerical Controlled (CNC) milling techniques to produce complex components in a fast and cost-effective manner. CNC machining controls rotating cutting tools via a computer programming interface. Following the program design, these tools systematically shape the source material into a customized finished product.

A number of common materials can be used in these processes, including:

• Aluminum
• Titanium
• Brass
• Wood
• Stone
• Copper
• Steel
• Stainless Steel
• Mechanical plastics (UHMW, Ultem, Acetal, Polycarbonate, Nylon, etc)
• Resins (fiberglass, carbon fiber, etc)

CNC milling facilitates the creation of highly accurate custom products from a variety of hard and soft production materials. The rotating tools, driven by their computerized instructions, progressively shave away, cut, and drill the material to create holes, slots, shapes, and other features required by the design.

There are four essential steps in CNC milling:

• Design. Using Computer Aided Design (CAD) modeling, engineers create visual representations of the desired end product.
• Conversion. CAD models are converted to Computer Aided Manufacturing (CAM) files, which instruct CNC machines on the necessary operations to realize the design.
• Set up. The machinery is set up to accept the programmed instructions and install the appropriate tooling so milling can begin.
• Operate. The CNC machine follows the program instructions, parts are inspected throughout production to ensure accurate finished products.

Throughout the process, engineers may adjust the programming to fit new parameters, implement improvements, or respond to unexpected situations.

CNC Milling Advantages

CNC milling offers a number of important benefits to manufacturers in different industries.

• Precision and uniform results. Five-axis CNC milling machines offer a high degree of accessibility and complexity, while minimizing fixturing requirements.
• High-volume production and scalability. After the initial set up, CNC milling machines can produce large numbers of components quickly. After programs have been optimized, the only way to scale machining production is through either additional milling centers, extending spindle hours per day via additional shifts, or through automation and lights-off tooling.

Labor costs are lower than manual milling, but this isn’t a good argument for CNC machining in this era. CNC Machining is one of the most expensive manufacturing methods and commands high hourly pay rates.With CNC milling, manufacturers make more products in less time with less risk of variation from the original design. There are plenty of new technologies that support variation mitigation, tool probes, dynamic offsets, in-tool diagnostics and vibration dampening, thermal indicators to reduce tool wear and heat warpage in parts, automated loading and unloading via robotics, and a long line of things.

CNC Milling Services

There are a number of choices for CNC milling operations. Each type has its own unique advantages and applications.

• Face milling employs a tool with teeth on both the periphery and face. This tool is used to make flat surfaces, smooth contours, and produce a higher quality finish than other shaping methods.
• Plain milling allows the shaping of large pieces of material. Wide cutting teeth allow the shaping of large areas of material while their narrower counterparts make deeper cuts.
• Angular milling adjusts the angle of cutters to produce chamfers, serrations, grooves, and other angular features.
• Form milling uses formed cutters to craft circular cavities, contours, and intricate patterns.
• Straddle milling is the process of cutting multiple pieces with one machine. Cutters are attached by an arbor and move simultaneously across adjacent surfaces.
• Gang milling uses multiple cutters on one machine arbor. These cutting tools are able to perform the same actions, creating complex parts in less time.
• Profile milling refers to the process of cutting vertical or angled pathways across the workpiece.
• This section seems to only have words that would come up if you googled “types of milling” but doesn’t seem to align with “choices for CNC milling operations” that is in the header. Drill, bore, ream, step/ramp mill, thread mill, tap, 3D contouring, swarf, high speed machining (constant engagement), are just some of the common operations.

There are also different types of CNC milling machines. Which machine is appropriate depends on the complexity and details of the design.

• A vertical mill orients the spindle axis vertically. This allows easier cutting and drilling of some materials.
• Horizontal mills operate on a flat, level plane. These devices are better for shaving and cutting.
• A turret mill features a stationary spindle on a table that can move in both perpendicular and parallel directions. These machines are highly versatile for their compact size.
• Bed mills are similar to turret mills. However, the tables on these machines only move in a perpendicular direction.

There are a number of components that make up CNC milling machines:

• Machine interface
• Column
• Knee
• Saddle
• Worktable
• Spindle
• Arbor
• Ram
• Machine tool

Each of these components is a vital part of producing parts. CNC milling is an integral process in the manufacture of a wide range of products—far too many to list here. Examples include:

• Car Engines
• Industrial equipment
• Aerospace components
• Furniture
• Cabinets
• Musical instruments
• Electronics
• Cell phones
• Construction/Infrastructure
• Consumer products
• Die making for injection molding/casting

CNC milling is a flexible method for producing highly customized components quickly, accurately, that avoids high initial tooling costs for production. Find out what CNC machining services from Pro-Type Industries can help your company save time, money, and frustration in your production processes.