What Are The Main Stages Of Metal Spinning

Metal spinning is an accurate and efficient method for making symmetrical metal components with many potential applications. Understanding the process and its steps in detail is beneficial because they can be replicated using PNC or CNC machines. These are just a few reasons why metal spinning is superior to other production methods; nonetheless, many individuals are put off by the process because they are unaware of what is required.

This blog aims to give a detailed explanation of the metal spinning technique that professionals use.

How Is Metal Spinning Done? 

Metal spinning involves shaping a metal sheet through a die or tool. When subjected to force, the metal assumes the form of the die. Consequently, the dimensions and specifications of this component are purposefully defined for each portion. A skilled metal spinner can do the spinning by hand, or automated PNC / CNC (Computer Numerical Control) equipment can do it, too.

Stages Of Metal Spinning

Metal Forming

An essential part of any industrial process is metal shaping. Its advantages, including cost-effectiveness, improved mechanical qualities, flexible operations, increased productivity, and significant material savings, make it an important industrial component in many manufacturing processes.

• Various manufacturing techniques are employed to transform raw materials into final goods. The following are some examples of manufacturing processes: casting, shaping, forming, connecting, coating, dividing, machining, and changing material properties.
• Forming is one of the most common manufacturing processes, and it has many uses in many different sectors, including the aerospace, automotive, and defence industries.
• Bulk or sheet-forming processes are used to create wrought material forms. Shaping, moulding, and casting are used to create cast items.
• Forming is commonplace in the automotive industry, including components like wheel rims, bodies, valves, chassis forms (rolled or stamped), oil pans, and more.
• Every day, we encounter countless shaped objects, such as pots, pans, toothpaste tubes, bike frames, chains, tube fittings, fan blades, and countless more.
• Plastic deformation is applied using tensile, compressive, bending, or shear stresses or a mix of these to mould the raw material into the required size and shape.

Forming Categorisation:

Metal-forming techniques usually fall under two main categories.

Bulk Forming Processes

Two types of metal forming exist: sheet metal forming and bulk-forming. When shaping raw materials with a low surface area to volume ratio, bulk deformation occurs. Bulk-forming includes rolling, forging, extruding, and drawing. Various forces can be employed in bulk deformation processing procedures, including compressive, compressive, tensile, shear, and combinations thereof.

Forming presses use a die and a collection of tools to conduct bulk-forming. Items made via bulk-forming include gears, bushed valves, and other engine components like connecting rods, valves, hydraulic valves, etc.

Sheet Metal Processes

Tensile and shear forces are the most commonly used in sheet metal forging. Sheet shaping mostly refers to working with sheets, plates, and strips. The majority of sheet metal activities are performed using hydraulic or pneumatic presses. Sheet working procedures use a set of instruments known as die and punch. Among the many sheet metal operations are drawing, shearing, blanking, and punching.

Powder Metal Forming

The distinctive properties of a relatively new type of forming process known as powder forming are causing it to rise in prominence. The capacity to create components with minimal material waste and near-final dimensions is a major strength of powder forming. This process is known as near-net-shape formation. It is possible to tailor the chemical makeup of materials to achieve specific mechanical qualities. When compared to traditional wrought metals, sintered metals have superior formability. Nevertheless, achieving zero or almost zero porosity remains a formidable obstacle in powder formation. Components with porosity have less strength, less flexibility, and worse corrosion resistance and, thus, are more likely to break before their expected lifespan is over.

How Are Metal Forming Methods Classified?

Bending

This method of metal forging is very adaptable. While it is most commonly done with a brake press, it can also be done with similar equipment. Metal sheets are punch-pressed by placing them over a die block. Die shaping involves applying a bending force to the metal rather than punching a hole in the sheet. Depending on the die type, bending can be further classified into several procedures, such as press braking, rotary bending, and roll bending.

Stretching

As part of the metalworking process known as "stretching," a die is used to bend and stretch a metal piece simultaneously. Using this, intricately shaped metal parts can be created. Also, it's great for shaping large-format metal parts with smooth surfaces that require precise radius bends. 

Deep Drawing

One more common method for shaping metal is deep drawing. A deep drawing involves clamping a metal sheet with a cavity onto a die. After being punched down, it's "drawn" through the hole (hence the name). The metal sheet is bent or formed like a cup or box according to the die. Metal parts or designs with a lot of detail are best made via deep drawing.

Roll Forming

Roll-forming shapes are metal components that are used in many sets of rollers. The roll-forming machine constantly presses the metal piece's surface with multiple pairs of rollers as it is fed through it. Using these, you may shape the metal into whatever shape you can imagine. Roll forming is a repetitive process that gradually shapes metal parts until they reach the desired cross-section. It works well for large production runs and is usually used to make long pieces.

Extrusion

Extrusion is a different kind of metal shaping that involves pushing a metal piece through a die. The desired cross-section is produced in this way. However, this technique is similar to the others. In extrusion, the metal is heated to a high enough temperature to soften it before it is forced on the die. When heated to such a point, the metal virtually becomes a fluid. The die has a hole in it through which the pressed metal, which is hot, flows.

Metal Trimming

Metal trimming is removing the extra material, mainly around the margins of a workpiece. As the last step in the shaping process, this is essential for giving the product its final form.

Why Is Trimming Used?

There are several reasons why trimming is an important production operation. Along with the steps outlined in the source material, this process ensures that the finished result is of the highest possible accuracy and quality. To ensure the product is made exactly as the design, trimming removes extra material. This process leads to a better final product.

In addition to enhancing the product's usefulness and longevity, trimming can also be utilised to eliminate weak places or probable failure sites. In addition to improving the product's aesthetics and making it more secure, trimming makes it easier to work with.

When trimming, consistency is key since it guarantees that every part is the same and fits the specifications, which is essential for mass production. As a result, trimming is a vital step with significant implications for manufacturing.

The Inherent Importance Of Trimming Operations

The many advantages of trimming procedures make them an integral aspect of sheet metal production.

Consistency and Precision 

It is impossible to exaggerate the significance of manufacturing precision and consistency. The automotive, aerospace, and medical device industries are particularly sensitive since even a small deviance from the requirements might have disastrous consequences. By eliminating the room for error, trimming procedures guarantee that every part manufactured is precisely according to the design parameters.

Appearance and Enhanced Quality 

A component's functionality and aesthetics contribute to its overall quality. Despite its usefulness, a component with noticeable flaws like rough edges or an uneven form could give the impression of being of inferior quality. Trimming raises the product's visual appeal, affecting buyers' evaluation of its quality.

Metal Finishing

The finishing of metals is the last stage of production, and it protects the environment and improves their beauty. Parts that need to mate or seal can also benefit from its usage to smooth off surfaces that are too rough for machining. Metal cleaning, deburring, descaling, and similar processes are also a part of it. Simply put, there is a wide range of applications for many metal finishing procedures. Several important finishing processes are covered in this article, along with their applications and things to consider when choosing a metal finishing procedure.

Variety Of Metal Finishes

Some examples of finishing processes are as follows:

Plating

Substrates can be coated or altered with thin layers of metals like zinc, cadmium, nickel, or chromium through metal plating, which involves chemical baths. Electroless plating uses an autocatalytic technique where the substrate catalyses the reaction, unlike electroplating, which uses an electric current to cover the substrate. Plating service providers are usually necessary because the process is chemically intensive and done on a huge scale.

Product longevity, resistance to corrosion, surface friction, and aesthetics can all be enhanced with metal plating. Zinc plating acts as a sacrificial anode in galvanised metal, corroding while simultaneously protecting the substrate underneath. In most cases, though, plating machines aren't the best choice for fixing surface imperfections.

Bolts, washers, and other small steel components can be coated with a zinc-iron alloy that is resistant to corrosion by the sherardising process. Applying a zinc dust coating involves tumbling the parts in a heated drum. This finish is extremely resistant to corrosion. A barrel-finishing machine offers a quick, effective coating option for large-scale manufacturing runs.

Cleaning/Brushing

Metal finishing using brushes is a more effective way to remove surface flaws than plating. These finishing machines make the grain pattern look more consistent and parallel to make a product look more polished. Typically, this effect is achieved by using an abrasive belt or wire brush. Perpendicular to the grain, the belt's or brush's solitary orientation can also provide somewhat rounded edges. Aluminium panels utilised for metal picture printing and signage undergo this finishing process.

Metal surfaces can also be prepared before cleaning by removing scale and grit using wire brushing, and slag can be removed from certain welding operations using the same method.

Before plating or coating, chemical or acid baths are utilised to remove oil residue that remains after forming, machining, and other procedures.

Vibratory Finishing

Deburring and removing sprue, sharp edges, and other debris is common for vibratory finishing equipment. They use tumble vibration to produce a uniformly random texture after positioning components inside a drum that contains abrasive pellets. The machine can effectively treat items ranging in size from very small to large because its cycle speed and vibration magnitude are typically adjustable.

Blasting

When a consistent matte finish is needed, sandblasting machines and other blast apparatus are usually brought into play. Sandblasting, sometimes called bead blasting, involves rapidly depositing abrasives such as sand, steel bullets, metal pellets, or a combination of these onto a surface. This makes for a polished end result for metals that aren't too hard.

For various metal surface treatments, such as increased resistance to fatigue, stress corrosion cracking, fretting, and more, shot peening is a blasting technique that imparts compressive stress. The cold working technique applies compressive tension as an antidote to the tensile stress that surfaces experience during production. The application of compressive stress for fatigue resistance can also be achieved through burnishing, another technique for cold-work surface modification.

Conclusion

The process of metal spinning encompasses a sophisticated and intricate journey from raw material to finished product, demonstrating a high degree of precision and efficiency in creating symmetrical metal components. This detailed examination highlights the critical stages of metal spinning, from initial forming through various methods such as bending, stretching, deep drawing, and extrusion to the essential finishing touches like trimming and advanced metal finishing techniques. 

Each step is integral to achieving the final product's desired quality, functionality, and aesthetic appeal. The versatility of metal spinning, facilitated by both manual skill and advanced PNC/CNC technology, offers a wide array of applications across numerous sectors, including aerospace, automotive, and defence, among others. 

By providing a clearer understanding of metal spinning's comprehensive stages and its significant role in modern manufacturing, this blog aims to demystify the process and encourage more professionals to consider its benefits. The adaptability, cost-effectiveness, and superior mechanical properties inherent in metal spun products underscore the value of this method, making it a superior choice in comparison to other production techniques.

Content Summary

• Metal spinning is a precise and efficient way to create symmetrical metal parts, and it is widely used in various industries.
• The process can be replicated with PNC or CNC machines, offering superior production methods.
• Despite its benefits, many shy away from metal spinning due to a lack of understanding.
• This blog aims to demystify the metal spinning process for professionals.
• Metal spinning shapes metal sheets through dies or tools, assuming the form of the die.
• Skilled spinners or automated equipment can perform metal spinning.
• Metal forming is crucial in industries like aerospace, automotive, and defence.
• Manufacturing techniques transform raw materials into final products through processes like casting, machining, and changing material properties.
• Forming processes, including shaping and casting, play a significant role in product manufacturing.
• The automotive industry heavily relies on forming components like wheel rims and chassis forms.
• Everyday items, from pots to fan blades, undergo forming processes.
• Forming uses stresses like tensile, compressive, and shear to mould materials into desired shapes.
• Metal-forming techniques are categorised into bulk forming and sheet metal processes.
• Bulk-forming involves shaping materials with a low surface area to volume-ratio through processes like rolling and forging.
• Items like gears and valves are often produced via bulk-forming techniques.
• Sheet metal processes use tensile and shear forces, working with sheets and plates through presses.
• Operations such as drawing and punching are common in sheet metal working.
• Powder metal forming is gaining prominence for its minimal waste and near-net-shape formation capabilities.
• Metal forming methods include bending, stretching, deep drawing, and roll forming.
• Bending can be done with brake presses, allowing for various types of bends.
• Stretching involves bending and stretching metal parts, ideal for large, smooth-surfaced components.
• Deep drawing forms metal sheets into shapes like cups or boxes, suitable for detailed parts.
• Roll forming uses rollers to shape metal parts, which is effective for long pieces and large production runs.
• Extrusion pushes metal through a die to achieve desired cross-sections, often involving heating the metal.
• Metal trimming removes excess material, ensuring products meet precise specifications.
• Trimming enhances product quality, longevity, and aesthetics while removing potential failure sites.
• Consistency in trimming is crucial for maintaining standards in mass production.
• Trimming operations enhance precision and consistency, which is crucial for industries like automotive and aerospace.
• A product's appearance and quality are significantly improved through trimming.
• Metal finishing, the final production stage, enhances both appearance and durability.
• Finishing processes include cleaning, deburring, and descaling, which are applicable across various applications.
• Metal plating involves chemical baths to coat substrates, enhancing longevity and corrosion resistance.
• Sherardising and barrel-finishing are methods for applying corrosion-resistant coatings.
• Cleaning/brushing removes surface flaws, improving a product's finish.
• Wire brushing prepares metal surfaces for further treatment, like plating.
• Vibratory finishing deburrs and smooths out parts, suitable for a range of sizes.
• Blasting techniques, such as sandblasting, create matte finishes and prepare surfaces for further treatment.
• Shot peening and burnishing improve metal resistance to fatigue and stress corrosion.
• Each finishing process has specific applications, influencing the choice of technique.
• Understanding metal spinning and finishing processes can lead to improved product quality and innovation.
• The versatility of metal forming and finishing techniques supports a wide range of product designs.
• Efficient use of resources and minimal waste make metal spinning and powder forming environmentally friendly.
• Automation in metal spinning, such as CNC machining, enhances precision and repeatability.
• The adaptation of forming processes to specific industry needs underlines their importance in manufacturing.
• Advances in metal forming and finishing technologies drive innovation in product design and functionality.
• The strategic choice of forming and finishing techniques can significantly impact production costs and efficiency.
• Metal spinning and trimming ensure the high quality of parts required by stringent industry standards.
• The detailed explanation of these processes aims to clarify their applications and benefits.
• Professionals in the field can leverage these insights for better decision-making in product development.
• By demystifying metal spinning and its stages, this blog encourages broader adoption and exploration of these techniques.