Why pressed shaftless flights and not rolled ones?
Unlike rolled flights, shaftless and pressed flights have the advantage that they have the same material thickness in the inner and outer diameters, giving better durability and strength.
BEMA produces shaftless screw conveyor flights in cold-formed steel. Cold-formed screw flights are more durable and stronger than hot-rolled flights. Hot-rolled flights might be preferable if a large number of flights are required in a standard application, as this will often be a more economical option.
Shaftless flights are e.g. used for sticky and oily media, such as might exist at wastewater treatment plants, in the feedstuffs industry, food industry, and similar. Furthermore, shaftless screw conveyors are used for conveying wood pellets to stokers as well as moving other large-grained granulates. Shaftless flights are resilient to some extent.