Metal spinning, a versatile forming technique, is commonly used to produce axially symmetric components for various industries, such as aerospace, automotive, and construction.
The process involves forcing a pre-sized metal disc to spin at high speeds on a lathe while applying force with a spinning tool to shape the metal into the desired form.
When embarking on a metal spinning project, understanding the range of available metals is crucial. Each metal offers unique properties that influence the outcome of the project, including durability, machinability, and cost.
Let’s get straight to the point
Metal spinning is a versatile technique used to create axially symmetric components for various industries. The choice of metal is crucial, as different metals offer varying properties that impact durability, machinability, and cost.
Common metals like aluminium, stainless steel, brass, and carbon steel are frequently used due to their balance of properties.
Specialty metals like titanium, copper, Inconel 625, and Hastelloy are chosen for high-performance or demanding applications, while precious metals like gold and platinum are used for luxury items.
Understanding these materials helps in making informed decisions for successful metal spinning projects.
Commonly Spun Metals
Aluminium
Aluminium is one of the most frequently used metals in metal spinning, known for its lightweight nature, corrosion resistance, and high strength-to-weight ratio.
Aluminium’s ductility and malleability make it easy to shape, making it a popular choice for various applications, from aerospace components to kitchen utensils.
- Visual Appearance: Silvery-white hue
- Characteristics: Low density, lightweight, non-toxic, and naturally resistant to corrosion.
- Uses: Widely used in the aviation, automotive, building, energy, healthcare, engineering, and food service industries.
Stainless Steel
Stainless steel is another common material in metal spinning. It is not a pure metal but an alloy of iron and other elements, which can vary depending on the specific type of stainless steel.
Its corrosion resistance, durability, and aesthetic appeal make it ideal for both functional and decorative applications.
- Visual Appearance: Matte grey finish
- Characteristics: Excellent resistance to corrosion, long-lasting, and simple to fabricate.
- Uses: Cooking utensils, water bottles, pans, knives, as well as aerospace parts, surgical instruments, and building materials.
Brass
Brass, an alloy of copper and zinc, is less commonly used than aluminium or stainless steel but still holds significant value in metal spinning due to its machinability and corrosion resistance. Brass is particularly favoured for its high strength levels, which are maintained even after shaping.
- Visual Appearance: Bright, golden colour
- Characteristics: Antibacterial properties, corrosion-resistant, ductile, and high strength.
- Uses: Common in the automotive, ornamental, musical instruments, and lighting industries.
Carbon Steel
Carbon steel is another metal commonly used in metal spinning. The amount of carbon in the alloy determines its characteristics, such as hardness and durability. Carbon steel can be further categorised into various types, including mild steel, alloy steel, and tool steel.
- Visual Appearance: Greyish-white surface
- Characteristics: Depending on the carbon content, it can be extremely hard and durable, with enhanced machinability.
- Uses: Utilized in construction, transportation, home furnishings, and manufacturing.
Specialty Spun Metals
Titanium
Named after the Greek mythological Titans, titanium is known for its strength, durability, and lustrous appearance. Although it is more expensive than aluminium or stainless steel, its lightweight and high corrosion resistance make it ideal for high-performance applications.
- Visual Appearance: Shiny, greyish-white metal
- Characteristics: Lightweight, extremely resistant to corrosion, and can withstand extreme temperatures.
- Uses: Found in the aerospace, medical, marine, and military industries.
Copper
Copper shares some similarities with brass but is generally more expensive and slightly harder to machine. Despite its cost and machining challenges, copper is chosen for its aesthetic appeal, with its reddish-brown colour providing a unique visual element to spun components.
- Visual Appearance: Reddish-gold colour
- Characteristics: Excellent conductor of heat and electricity, highly ductile, antibacterial, and resistant to corrosion.
- Uses: Roofing, energy production, marine applications, plumbing, and the automotive industry.
Inconel 625
Inconel 625 is a nickel-based superalloy known for its high tensile strength, corrosion resistance, and fatigue resistance. Although it is more challenging to machine than other metals, its properties make it indispensable in demanding environments.
- Visual Appearance: Similar to stainless steel but lighter
- Characteristics: Very weldable, resistant to corrosion and fatigue, with excellent mechanical properties.
- Uses: Widely used in the chemical processing, engineering, petroleum and gas extraction, and nuclear sectors.
Monel
Monel is another nickel-copper alloy that stands out for its acid resistance and corrosion resistance. This makes it a suitable choice for applications where exposure to harsh environments is expected.
- Visual Appearance: Metallic grey
- Characteristics: Acid and corrosion-resistant, easily brazed, soldered, and shaped.
- Uses: Common in the marine, aerospace, chemical processing, and engineering industries.
Rare and Precious Metals
Gold and Platinum
Gold and platinum are precious metals that are sometimes used in metal spinning for high-end, luxury products. These metals are chosen for their unique appearance, high resistance to corrosion, and prestige.
- Gold Visual Appearance: Bright yellow
- Platinum Visual Appearance: Silvery-white with a high luster
- Characteristics: Both metals are extremely corrosion-resistant, durable, and have a high melting point.
- Uses: Often used in jewellery, electronics, medical equipment, and as decorative accents in high-end products.
Tungsten
Tungsten is a hard, dense metal with exceptional corrosion resistance and a high melting point. However, its hardness makes it difficult to machine, which is why it is not commonly used in metal spinning except for specific applications where these properties are essential.
- Visual Appearance: Silvery-white metal
- Characteristics: Extremely hard, corrosion-resistant, and has a very high melting point.
- Uses: Primarily used in aerospace, defence, mining, and electronics industries.
Hastelloy
Hastelloy is a nickel-based alloy known for its excellent resistance to corrosion and high temperatures. This makes it a preferred choice in environments that would degrade other materials.
- Visual Appearance: Metallic grey with a shiny finish
- Characteristics: Low silicon content, ideal for welding, and highly resistant to corrosion.
- Uses: Used in mining, chemical processing, oil and gas, and marine industries.
Factors to Consider When Choosing a Metal for Spinning
Machinability
Machinability is a critical factor in metal spinning. Metals like aluminium and brass are known for their ease of machining, while others like tungsten and Inconel 625 require more specialised equipment and expertise. Machinability affects not only the ease of production but also the final cost of the component.
Durability
Durability is another essential consideration, particularly for components exposed to harsh environments or high stress. Metals like stainless steel, titanium, and Hastelloy offer excellent durability, making them suitable for aerospace and medical applications.
Cost
Cost is often a determining factor when selecting a metal for spinning. Common metals like aluminium and carbon steel are more affordable, while specialty metals like titanium, Inconel 625, and Hastelloy can be significantly more expensive due to their properties and the complexity of machining them.
Conclusion
Metal spinning is a versatile manufacturing technique used across various industries, from aerospace to construction.
The choice of metal plays a crucial role in the success of a metal spinning project, affecting everything from machinability and durability to cost and appearance. Commonly spun metals like aluminium, stainless steel, and brass offer a good balance of properties, making them suitable for a wide range of applications.
On the other hand, specialty and precious metals like titanium, copper, Inconel 625, and platinum provide unique advantages for more demanding or luxurious applications.
Understanding the properties and uses of these metals allows you to make informed decisions, ensuring that your metal spinning project meets the desired specifications and performance criteria.
