OEM Specs for an 80 x 600mm Cross Flow Fan Impeller

OEM Specification for a Motorless Fan Unit

The customer asked for a custom fan assembly. Meanwhile, they build specific HVAC units. Their order requires 3,000 sets each month. Therefore, we received the cross flow fan impeller request in April 2026. The customer needed an 80mm diameter fan wheel. In practice, the nominal wheel length had to be 600mm. We call this a metal cross flow fan impeller. Next, they needed this part enclosed in a metal housing. But the customer made a rare choice. They asked us to leave out the cross flow fan impeller. Also, they did not want any bearings. In short, they just needed the bare rotating wheel and the casing.

This setup has strict physical limits. The design needs a steel shaft. The shaft diameter is exactly 6mm. One end must extend by 25mm. Also, the wheel must spin in a right-handed direction. The size limits were very tight. We had to fit the whole unit inside a 120x120mm box. At the same time, the total length could not pass 650<1.5mm. Therefore, we had to control every dimension strictly. We followed the GB/T1804-v standard for all part sizes. Finally, the safe operation of the unit had to meet the GB/T13933-2008 standard.

Engineers use these long fans for specific jobs. You see them in wide cooling racks. Sometimes they go into air curtains. By dropping the motor, the customer saves space. They can use their own drive systems. Thus, they keep full control over their motor speeds. Now, our job was purely mechanical. We focused on making the metal frame strong. We also made sure the blade shape moved air well.

Building the Bare-Shaft cross flow fan impeller

Connecting the External Motor

First, we looked at the shaft connection. We do not supply the motor for this unit. Therefore, the shaft must link perfectly to the customer’s motor. The drawing asks for a 6mm steel shaft. It must stick out by exactly 25mm. We chose a solid steel rod for this task. Then, we paired it with a 6mm steel sleeve. This choice gives the fan great stiffness. By contrast, a long fan wheel can bend easily. If we used soft metal, the shaft would warp. Then the blades would scrape against the housing. The steel parts add a little weight. Yet, they stop mechanical failures. Consequently, the customer gets a part that lasts longer.

Choosing the Blade Design

Next, we checked the wheel design. The system needs right-handed airflow. In fact, our standard 80mm wheels use 30 blades. However, the space inside the housing is very tight. The box is only 120x120mm. So, a 30-blade wheel did not push enough air. Instead, we built a 36-blade aluminum cross flow fan impeller. This change boosts the air flow. We completely ruled out a plastic wheel. Plastic bends too much at a length of 600mm. You would need extra supports in the middle. Thus, we chose an aluminum alloy plate. This material costs more than plastic. But it stops the wheel from sagging. The metal handles the spinning force very well.

Building the Metal Casing

Finally, we designed the outer box. We call this the volute. The sides and main shell use SGCC steel. This is a hot-dip galvanized metal. We used rivets to put the shell together. We did not weld the metal joints. Welding can warp thin steel with high heat. Riveting keeps the shape flat and true. This method took more time in the factory. As a result, the labor cost was higher. Accordingly, we accepted this added cost. It allowed us to meet the strict 650±1.5mm length limit. The rivets close all the gaps nicely. The final model is LW-80620-01. It fits the exact space the customer requested.

Technical Specifications

We list the specific numbers from the engineering documents below. Indeed, these figures guide the system integration.

The size numbers tell you how to fit this unit. For instance, the 620mm wheel length leaves exactly 15mm of empty space on each side inside the 650mm casing. Therefore, the buyer must line up their motor perfectly with the 6mm shaft.

Reference: AMCA 210 covers the test method behind these figures.

Technical Documentation

This catalog image displays the standard size ranges for our aluminum wheels.

LW-80620-01 Mechanical Drawing

System designers need this exact dimension drawing to plan their mounting holes. Also, they need it to match the shaft position.

Integrating a Motorless Fan Assembly

If you need a cross flow fan impeller without a motor, you take on more design work. Your team handles the power and the mounting.

• First, measure the vibration of your own motor. A long steel shaft will carry any shaking across the whole fan. If your motor vibrates too much, the fan wheel will hit the metal casing.
• Next, check the spin direction of your drive system. You must match it to the fan. A right-handed fan will not push air well if you spin it to the left.
• Also, pick your frame metal carefully. We used SGCC steel because it stays flat over long distances. Thin plastic frames warp easily when the fan is long.
• Finally, share your exact box size and shaft limits with your supplier. We make the aluminum wheels in our own factory. Thus, we can easily change the blade count and length for your first sample.

Related: Cross Flow Fans.

Common Engineering Questions

Browse our cross-flow fans range, the AC cross-flow fans section, or cross-flow impellers.