Some Details About Steel Pole

The core difference between making light poles directly from galvanized steel sheets and making them from steel sheets first and then galvanizing lies in the sequence of the galvanizing process, with distinct variations in rust resistance, appearance, precision, cost, and application scenarios.

Making light poles directly from galvanized steel sheets follows the logic of "galvanizing first, then processing". It starts with purchasing finished galvanized steel sheets (either hot-dip galvanized or electro-galvanized), which then undergo mechanical processing such as cutting, CNC bending, pipe rolling, welding, and polishing to form light poles. The advantages of this process are focused on appearance and efficiency: the galvanized steel sheets themselves have a smooth and flat zinc layer. After processing, the light poles do not need to undergo the "secondary high-temperature exposure" of galvanizing, so their dimensional accuracy is easy to control, and the surface has no granularity. This makes them perfectly suitable for scenarios requiring high appearance quality, such as municipal landscape lights and commercial district decorative lights. Additionally, the processing cycle is short, eliminating the need to wait for the extra galvanizing procedure. However, it has a significant shortcoming in rust resistance: the cutting edges and welding seams formed during processing will completely damage the original zinc layer. If these "exposed" steel parts only rely on post-painting or local re-galvanizing for protection, not only is the process cumbersome, but the bonding force between the repair layer and the original zinc layer is weak. When exposed to outdoor wind, rain, ultraviolet rays, and salt spray for a long time, the repair layer is prone to peeling and cracking, eventually becoming a "breakthrough point" for corrosion. In coastal, rainy, and high-humidity environments, the corrosion rate is 3-5 times faster than that of light poles with a complete zinc layer.

Making light poles from steel sheets first and then galvanizing adheres to the logic of "processing first, then galvanizing". It begins with using ordinary black steel sheets, which are cut, bent, pipe-rolled, welded, and polished into semi-finished "black poles", and then the entire light pole is sent to a hot-dip galvanizing bath (the mainstream process) for galvanizing. The core advantage of this process is its excellent rust resistance: the high-temperature zinc liquid can fully infiltrate the surface of the light pole, including hidden parts such as welding seams, edges, and inner walls. Zinc undergoes a metallurgical reaction with steel to form a tightly bonded zinc layer with uniform thickness and strong adhesion, which can effectively isolate air and moisture from contacting the steel. The rust resistance life can usually reach 20-30 years. However, it also has obvious drawbacks: the high temperature of hot-dip galvanizing will form a natural granular zinc flower appearance on the surface of the light pole, which is slightly rough, and the high temperature may cause slight deformation of the light pole, affecting dimensional accuracy to a certain extent. At the same time, the additional galvanizing process increases processing costs and production cycles. Nevertheless, its comprehensive rust resistance makes it the preferred process for scenarios with high rust resistance requirements, such as outdoor roads, highways, coastal areas, and industrial parks.