How are wheels made?

There are many wheel construction types which may impact appearance, fitment, performance and cost. Some wheels are cast in a mold using melted aluminum while others use components and machinery to create more custom options.  Your choice in construction type will depend on your needs and budget.   

CAST WHEELS

Cast wheels and cast components are produced by introducing melted aluminum into a mold then allowing it to cool and harden to create the design.  The molten aluminum is inserted into the mold using one of a few methods:  

1. Gravity Casting: Gravity is used to pour the aluminum which creates the force needed to fill the mold. This allows for a simple, cost effective method. Aluminum is not as densely packed as other processes so gravity cast wheels may be denser to achieve the same level of strength.
2. Low-Pressure Casting:  Molten aluminum is rapidly pumped into the wheel mold using low air pressure to create a dense, strong product with fewer imperfections. This is a common method because it creates a lighter, stronger wheel without an increased cost.
3. High-Pressure Casting:  Uses a higher air pressure to pump molten aluminum into a wheel mold for a denser, stronger final product.  High-pressure castings can be priced higher than low-pressure castings but may not exhibit any notable gains in strength or weight.

One-Piece Cast

The most common aftermarket wheel is the 1-piece cast wheel where the entire wheel is "cast" using molten aluminum in a single mold.  The finished casting is machined as needed and followed by heat treating for added strength. The wheels are then typically finished with either paint, polish or chrome.  The casting process produces a strong wheel with a lower cost than most custom options.  You’ll find cast wheels in a wide variety of sizes and finishes, which makes them a great option for daily driving and budget builds.

Two-Piece Cast Center

A 2-piece cast wheel is constructed using a cast center welded into a spun outer.  The center is made in a mold just like the 1-piece cast wheel but the separate outer allows the user to choose a custom backspace. The material of the outer is lightweight which reduces the overall weight of the wheel and provides additional benefits.

FORGED WHEELS

There are a variety of forged construction options including monoblock and multi-piece wheels.  Each offers its own set of advantages.

Monoblock

Monoblock wheels are manufactured from a solid blank forging which is machined to the desired design. The 6061-T6 aluminum used is valued for its strength, light weight, appearance, machineability and versatility. It is widely used in aerospace, automotive and other applications where high strength and low weight are required. The process of creating the forged blank tightens and aligns the molecules in the aluminum which increases the strength of the material.  A forged monoblock wheel is approximately 30% stronger than a traditional cast wheel. Some forged monoblock wheels are rated with a load capacity exceeding 4,000 pounds!

Additionally, 6061-T6 alloy has less porosity than a cast wheel which allows for a high-luster polish that’s comparable to that of a chrome finish.  The low porosity also reduces oxidation (fading) of the polish making them low maintenance compared to a polished cast wheel.

Monoblock wheels demand a premium price for several reasons including:

• Premium 6061-T6 material
• Engineering costs
• Machine time (labor $/hr)
• Scrap material (the alloy shavings that are cut from the blank)
• Custom finish options

Mono 2

Mono 2 wheels utilize two components for construction.  The face of the wheel includes the front tire bead seat and is manufactured in the same way as a monoblock wheel using a forged blank for the front which is then bolted to a spun forged rear.  This allows flexibility in rim widths and offsets for custom fitments. The hardware used for joining the components may be exposed or hidden.

Advantages of Mono 2 wheels include:

• Light weight
• Different rear width options are ideal for staggered fitments
• Easy two-tone finish options
• Provides both concave and flat profile options

Forged Center Two-Piece (Welded)

Two-piece forged center wheels are constructed similar to the Mono 2 wheel, however the face of the wheel does not include the tire bead seat.  The forged wheel design is cut from a blank which is then welded to an outer containing both the front and rear bead seats. Like the Mono 2, this construction allows flexibility in rim widths and offsets for custom fitments.

The advantages of 2-piece wheels include:

• Light weight
• Different width options are ideal for staggered fitments
• Customizable offsets
• Modular design allows easy barrel replacement for repair of a bent lip

Forged Center Two-Piece (Bolted)

The construction of 2-piece bolted forged wheels consists of a forged center bolted into a cast barrel.  The cast barrel contains a flange for bolting the center. 

Benefits of 2-piece bolted wheels include:

• Reduced cost for the cast outer
• More finish options than welding

Forged Three-Piece

3-piece wheel construction consists of three components:

• Center
• Outer barrel
• Inner barrel

The center is attached between or on top of the barrel components.  As with the Mono 2 construction, the bolts can be either hidden or exposed. Having the barrel in two pieces allows more flexibility with widths, lip depth and finish combinations.   

The advantages of 3-piece wheels include:

• Light weight
• Flexible rim widths and lip sizes
• Ideal for staggered fitments
• Most finish flexibility
• Modular design allows easy barrel replacement for repair of a bent lip

FLOW FORM 

Flow form wheels are made by applying heat and pressure to extrude a cast wheel face along a flow form spool to create the size and dimensions of the final wheel. The heat and pressure of the extrusion process realign the molecular structure of the aluminum making the material stronger.  This results in a stronger wheel that is 15% lighter than a one-piece cast wheel.  The strength of flow form wheels make them a great choice for “spirited” driving.

There are several benefits to light weight wheels including:

• Improved acceleration
• Improved braking
• Enhanced cornering and handling
• Better fuel economy
• Less wear in suspension parts
• Longer EV battery life

For more on Flow Form check out this video from one of our many brands that utilize this technology:  Flow Form Explained

FUSION FORGED