Also known as spin forming, metal spinning is a process manufacturers use to craft axially symmetric metal parts without cutting the material. This process is efficient and highly versatile. At Helander, we have spent over 80 years providing superior quality metal spinning services to our customers in the aerospace, commercial, medical, and defense industries.
What is Metal Spinning?
Manufacturers opt for metal spinning when they need to create conical, dished, domed, flanged, flued, hemisphere, semi-elliptical or trumpet shaped parts or hollow components with a circular cross-section. This metalworking process is unique in that it does not involve removing material from a workpiece to shape the desired component. Instead, an operator will take a metal disc, known as a blank, and transform it by rotating and forming it to a mandrel. The process can be performed either hot or cold, depending on the particular material to be spun.
To start the process, the blank metal is clamped between the follower and the mandrel. As these three parts begin to rotate, the mandrel presses into the blank. This stage of the process can be done manually, with the operator pressing the mandrel by hand, or with auxiliary power. After the mandrel successfully forms the part, the operator may trim the ends and finish it with a spinning tool moving between 300 rpm and 1,200 RPM typically.
Metal spinning is an affordable and efficient process with tooling costs that are often 10 percent of alternative metal forming processes. Additionally, manufacturers create metal spun components in just weeks. The speed of this process provides a higher level of design flexibility, as it is easy for operators to change metal spinning tools as the product design evolves.
Metal spinning is ideal for applications requiring a high level of strength and durability. This process results in high-quality finished parts with no welds or seams. In addition to increasing strength, the smoothness of metal spun parts provides an aesthetic appeal that may be desirable in certain applications.
Types of Tools Used for Metal Spinning
There are three broad categories of metal spinning tools:
- Internal Tooling: Material is formed over the mandrel.
- External tooling: material is formed inside of a hollow mandrel.
- Collapsible: Shapes parts with variable diameters through the use of a removable center core.
In general, spinning tools are composed of either steel, plastic, or wood. The following types of machinery play vital roles in the metal spinning process:
This lathe bed is the base of the machinery. It supports all other components during machining.
This forming die gives the blank its final shape. The operator will stretch the blank over the mandrel as it spins, ensuring a smooth final part.
The roller provides the force that shapes the workpiece over the mandrel as it spins. This tool maintains a controlled contact to ensure the final component has a uniform wall thickness. It can be operated manually, but requires a high level of skill and is often automated instead.
Serving as a base for the mandrel, the spindle rotates the mandrel as it forms the final part. The primary spindle is located on the headstock, with an additional spindle located on the tailstock.
This frame controls the RPM of the machinery, supporting the spindle and mandrel throughout the process.
Located at the opposite end of the machinery, the tailstock provides the pressure that clamps the metal blank in place during forming.
Attached to the tailstock, this pressure pad clamps the workpiece in place as the tailstock provides pressure. The base of the final component will correspond with the size of the follower.
Metal Spinning Materials
The metal spinning process is compatible with many materials, each offering different properties.
Aluminum is the most popular metal spinning material and is the metal of choice for products that must be lightweight and affordable. It is low density and malleable, with strong corrosion resistance.
Naturally conductive and antimicrobial, copper is one of the most popular metal spinning choices. It is non-magnetic, resistant to tarnishing, and aesthetically appealing.
Stronger than copper, brass provides similar antimicrobial, conductivity, and workability properties. It also offers significant aesthetic appeal.
Bronze is slightly heavier than steel, and it performs well in extreme temperatures and high-friction applications. It is very durable and offers impressive electric conductivity properties.
Thanks to its durability and cost-effectiveness, carbon steel is very popular for rigid parts. The addition of carbon increases its strength but decreases its malleable properties.
Sometimes referred to as high-strength steel, Inconel offers elevated resistance levels to oxidation, corrosion, pressure, and heat.
For high-stress applications, Hastelloy provides better performance than many traditional metals. This exotic alloy is composed of over 22 different elements. These include copper, chromium, iron, and manganese.
One of the most popular metal spinning materials, stainless steel provides an impressive strength to weight ratio and high levels of corrosion resistance. It is cost-effective and easy to work with.
Slightly more expensive than steel, titanium offers high levels of tensile strength. It is durable, low density, and provides long-lasting performance.
Applications for Metal Spinning
The versatility and cost-effectiveness of metal spinning make this process a popular choice across a wide range of industrial and commercial applications. A few of the most common applications for metal spun parts include:
- Aircraft components
- Foodservice equipment
- Architectural and lighting
- Musical instruments
- Heavy industrial components
- Gas cylinders and pressure vessels
Metal Spinning Services at Helander
Metal spinning results in seamless components that are uniform, durable, and incredibly well constructed. This process offers low costs and rapid turnaround times in both small and large runs. At Helander, we have spent over 80 years crafting custom metal-spun components for our customers. We tailor each piece to the specifications of the project, working with parts in a range of diameters and material thicknesses. To further streamline production, we offer a range of in-house welding and finishing services.