Manufacturing Difficulty
This conical screw flight was one of the most challenging types of spiral flights to manufacture because both the inner and outer diameters changed continuously from large to small.
The production of a screw flight mainly depends on four key parameters: outer diameter, inner diameter, pitch and plate thickness. In this project, all four parameters were outside the normal production range.
The maximum outside diameter was 1.2 meters, while the smallest diameter was 430 mm. In addition, the flight thickness reached 50 mm, making forming and dimensional control much more difficult compared with standard screw flights.
As this was a one-piece trial order, successful production on the first attempt was critical because re-manufacturing such a large and thick flight would involve significant additional cost and time.








Solve problems for production
To overcome the manufacturing challenges, our engineers calculated the developed dimensions carefully and adjusted each production step according to the actual behavior of the 50 mm steel plate.
The screw flight blade was fabricated by welding three sections together. To maintain the same rotation center and improve concentricity, we used the static balance method to determine the correct center position.
In addition, dedicated welding tooling was developed for this project to hold the flight position during welding and improve dimensional accuracy after assembly.
Through careful calculation, tooling preparation and production control, the conical screw flight was successfully completed in one production run.
Material
The conical screw flight in this project was manufactured from carbon steel. For different working environments, we can also supply stainless steel, low-alloy steel and wear-resistant steel options according to requirements such as corrosion resistance, abrasion resistance and operating conditions.
Yutung Screw Flight Reference links
For related screw flight solutions, see our Sectional Screw Flight and Continuous Screw Conveyor Flight pages.
For another New Zealand project using the same large conical screw flight concept with a reduced thickness of 40 mm, you can also view OD 1.2m with Thickness 40mm Conical Screw Flight.
For more information about customized screw conveyor components and flight manufacturing, you can also read Bühler Conveyor Screw Components Manufacturer.

































