In the wheel industry, monobloc and 3-piece are two of the most popular types of forged wheels. The terms “monobloc” and “3-piece” refer to the construction of the wheel, but the similarities end there. In fact, there are many differences between the two types that make each ideal for different types of automotive applications.

Monobloc wheels are also known as “one piece” wheels, meaning they are forged in one piece with no removable components. During the manufacturing process, a monobloc wheel begins as a single round block of 6061-T1 aluminum alloy. The aluminum block is compressed and subjected to intense heat which creates a dense grain structure and forms a round piece of metal blank. The single piece of aluminum alloy is then flow molded and placed into a CNC mill where the spokes are formed to finalize the manufacturing process.

Since the monoblocs are made from a single piece of aluminum alloy, they are the lightest forged wheels. Their low weight is sought after, as they help reduce unsprung mass, which can reduce acceleration times, improve braking and improve handling. Monobloc wheels are typically less expensive than their 2- or 3-piece forged counterparts since fewer parts are used for construction. However, if a monobloc wheel is damaged or bent, it is difficult to repair and often requires a complete wheel replacement.

3-piece forged wheels offer different advantages over monoblocs, mainly from a styling point of view. A 3-piece wheel has three main parts: a hub, the outer rim or “lip,” and the inner rim. The manufacturing process for 3-piece wheels is similar to that of a monoblock, except that more aluminum alloy blocks are used due to the greater number of parts. Once all the pieces have been milled, they are joined by means of a series of perimeter screws and sealed with RTV Silicone.

3 piece forged wheel construction allows manufacturers the ability to offer a wider range of widths and fits for customers. 3-piece wheels are also the most customizable, as any of the components can be easily painted or chromed to create a unique color scheme. If they are damaged, they can be easily replaced. Plus, 3-piece forged wheels retain the highest resale value among used wheels. 3-piece wheels are not without their drawbacks. They are the most expensive forged wheels because they are manufactured in several pieces, and if the RTV Silicone seal is broken, leaks can form.