HZ Roll Forming steel structure purlins are important secondary components in steel structure factories and other buildings. In the quotation list of steel structure factories, they are usually included in the steel structure parts and generally need to be listed separately.
HZ Roll Forming steel structure purlins are generally made by cold bending hot-rolled sheets, featuring thin walls and light weight, excellent sectional performance, and high strength, with materials ranging from Q195 to Q345. Common steel purlins include Z-shaped steel purlins and C-shaped steel purlins. Steel purlins are secondary load-bearing components in the roofing structure system, transmitting roof loads to the steel frame. In factory applications, roof purlins and wall purlins are used.
C-shaped steel, meticulously crafted using advanced hot-rolled sheet cold-bending technology, is characterized by its lightweight and strong load-bearing properties, showcasing excellent sectional performance and high strength. It is rolled using a high-precision forming machine to ensure a flawless surface finish and extremely high dimensional accuracy. In terms of material selection, we cover a wide range from Q195 to Q345 to meet the strength and performance requirements for different applications.
The angles of Z-shaped purlins and C-shaped purlins are different. The C-shaped purlins form a 90-degree angle, while the Z-shaped purlins form an angle less than 90 degrees, roughly between 60 to 75 degrees. When using purlins for roofs with a certain slope, the angle of the purlins should be considered based on load-bearing knowledge. For steep slopes, Z-shaped purlins can fully utilize their bending performance.
Compared to the Z-shaped cross-section, the mechanical performance difference between the strong and weak axes of the C-shaped cross-section is significant, and connections to the steel frame are mostly bolted hinges, which should be considered as simply supported during calculations (Z-shaped sections can achieve rigid connections through reliable lap joints, allowing for continuous beam calculations). Thus, from the perspective of load-bearing state, calculation results, and structure, the latter is more reasonable. Therefore, except for special node processing such as doors and windows, Z-shaped sections should be preferred. Wall purlins and roof purlins with small slopes can use C-shaped sections; for roof purlins with larger slopes, Z-shaped sections are preferred, ideally allowing the resultant force of the roof load to pass through the centroid of the Z-shaped purlin cross-section.
When the roof slope is small, the bending section modulus of Z-shaped purlins is slightly larger than that of C-shaped purlins, but the difference is not significant. When the roof slope increases, the utilization rate of the bending section modulus symmetric to the vertical direction of the Z-shaped purlins increases. Therefore, Z-shaped purlins are suitable for roofs with larger slopes; for walls, there is not much difference between choosing Z-shaped or C-shaped; if purlins are intended to be continuous components, Z-shaped purlins are preferred due to their convenient lap joint.
