Stainless Steel Angles as Tread for Conveyor Wheels
When an angle bar is used as the running surface for polyurethane wheels, it stops being a structural component and becomes a precision one. The wheels track along the leg for the entire length of the conveyor, so any deviation in straightness or any roughness on the surface turns directly into vibration and uneven wear. A customer building a multi-axis conveyor belt system needed angle profiles of 65x30x5 mm in stainless steel 304L for exactly this duty, in prototype quantity and in a short time. Montanstahl supplied them laser welded, with straightness and twist below 1 mm per metre and a surface that needed no further treatment, in two weeks.
Conveyor Systems and the Profile the Wheels Run On
A belt conveyor system is built around two motorized pulleys that drive a closed loop belt, moving the belt and the material on it forward as they rotate. Conveyors of this kind run through warehouses for automated distribution and through manufacturing plants to move material along the production line, and they remain one of the foundations of industrial automation in every sector. Inside such a system the guiding elements do the quiet work. Polyurethane wheels roll along a metal tread that has to stay flat, straight and smooth over long distances, because the belt path is only as accurate as the surface guiding it. In this project the customer was developing a prototype profile for an external handling system, which is why stainless steel was specified from the outset, since a tread exposed to weather cannot rely on paint or on a coating that the wheels would gradually abrade. Applications like this recur across the sectors Montanstahl serves, from mechanical engineering to logistics.
Straightness, Roughness and a Prototype Deadline
The customer asked for angle bars in stainless steel 304L to serve as the tread for polyurethane wheels, and the specification came down to three parameters. The first is straightness, since the bar has to be rectilinear for the system to move properly, and a bow along the length translates into the wheels loading and unloading as they pass. The second is surface roughness, capped at 6 Ra micrometres so the wheels slide smoothly, because a rougher tread increases rolling resistance and wears the polyurethane faster. The third is time, because the profile was needed for a prototyping phase and a long lead time would have held up the whole development cycle. Each of these is manageable in isolation. Together they exclude most routes, since hot rolled angles do not usually reach that surface class without additional finishing, and machining a bar to specification is slow and expensive for a component that is essentially a length of angle.
Application Context
Laser welded profiles answered all three points at once. Because the heat input during welding is low, distortion stays limited and the bars hold a straightness and twist below 1 mm per metre, which is what makes them suitable as guiding components in this kind of machinery. The standard surface finish for laser welded profiles falls in a roughness range of 3.5 to 5.5 micrometres, comfortably inside the 6 Ra limit, so the sections needed no extra treatment before being used where a smooth running surface is required, although polishing or brushing remain available when a project asks for them. The rapid production process allowed delivery of the bars in two weeks, matching the pace of the prototype phase. Sections of this kind are part of the Montanstahl range of unequal leg angles and the wider stainless steel angles programme, with the surface and tolerance advantages of the process described in our article on laser welded profiles in stainless steel. Questions on sizes and finishes are answered in the technical Q&A.