Q345 square and rectangular pipe is a material commonly used in the industrial construction industry. The demand is large. There are many Q345 square and rectangular pipe products on the market, and the quality is uneven. When choosing, pay attention to the selection method:
1. Look at the size
You can use a vernier card measuring tool to simply measure whether the actual size is about one specification or more smaller than the marked size. Generally, there is not much difference between good Q345 square and rectangular pipes. In addition, it should be noted that some inferior square pipes will deceive people's vision by smashing the mouth. Therefore, when viewed from the end face of the steel pipe, it is an oblate oval shape, while the end face of regular steel pipes should be basically round.
2. Look at performance
Q345 square and rectangular pipes have certain tensile and compressive properties, so we can also consider these aspects when selecting square pipes: tensile strength is the basic performance of square pipes. The greater the tensile strength, the better the performance of the square pipes; compression and bending resistance should also be taken into consideration.
3. Look at the surface quality
Inferior square tubes are rolled with unqualified raw materials and have poor surface quality, often with scars and other defects, and have an overall rough feel. Some small steel mills have a reddish surface color due to insufficient heating temperature and rolling speed. High-quality Q345 square and rectangular tubes pass the quality standard, with no obvious defects and bright white color.
4. Look at the packaging
Regular Q345 square and rectangular pipes are mostly packed in large bundles when they leave the factory. The bundles of steel are hung with metal labels corresponding to the actual products, indicating the manufacturer, steel grade, batch number, specification and inspection code, etc.; while Q345 square and rectangular pipe products are packaged in small bundles (about ten bundles) or in bulk, and do not have metal labels or quality guarantees. Special attention should be paid to Q345 square and rectangular pipe products without metal labels and quality assurance certificates.