Differences between cast, flank, and point milled wheel

Among the various compressor wheel options, if you find it hard to choose, let’s talk about their differences today. We will focus on cast wheel, flank milled wheel, and point milled wheel.

The earlier generation turbochargers use casting wheels. By its name, you may notice that they are casted (pour casting), but do you know characteristics of a casted wheel? In general, casting parts tend to have air bubbles during the production procedure, and air bubbles effect its durability, therefore gradually, billet wheels are introduced.

Billet wheels are forged wheels, they are machined from a solid piece, therefore they have better durability and they withstand extreme pressure. With forged production, the blade aerodynamics are designed differently than the casting wheels for the following features. Earlier billet wheels are mostly flank milled wheels, flank milled wheels expedite spool by around 7% depending on your setting. They also give you a little extra response and about 10% gain in airflow. Their durability also provides higher pressure ratio. Performance wise they even create some extra power than the casting wheels.

Point milled wheels were released the last among these three types. Same as the flank milled wheels, they are forged but require more machining time and cost as the tool goes over on the blade using multiple passes. This machining method also allows more complicated geometry. With Arashi point milled wheels, the updated blade aerodynamics increases horsepower by 20% due to better airflow, they also allow the optimized wheel design to reach maximum efficiency. When you tune your vehicle, they offer you a wider range for your power output.

With their characteristics said, many also wonder about their differences in weight. Here, we would like to justify that a billet wheel is not necessarily lighter than a casting wheel, nor a billet wheel is heavier than a casting wheel. Why? There are tons of compressor wheel designs out there, unless you take two specific compressor wheels (billet or casting) and weigh them, you can’t determine which one is lighter by its production method, in other words, casting wheels or billet wheels. Often times in order to improve their overall performance and efficiency, billet wheels are added with features like taper tips, slim nose, slim hub, high pitch, and high blade, these definitely impact their weight. You certainly cannot be sure of a wheel’s weight by how it’s made. Therefore, if you certainly have to take weight into consideration, please weigh them individually.