The quality requirements for steel pipes

The quality requirements for steel pipes used in construction mainly involve materials, specifications, appearance, and safety performance, and specific standards vary depending on the application scenario (such as scaffolding, structural support, etc.).

Material requirements  材料需求
Scaffold steel pipe: Q235 steel with an outer diameter of 48.3mm and a wall thickness of ≥ 3.6mm should be used, and there should be no severe corrosion, cracks, or deformation. ‌
脚手架钢管：应使用外径 48.3 毫米、壁厚≥3.6 毫米的 Q235 钢材，且不得存在严重腐蚀、裂纹或变形。
Seamless steel pipes: divided into structural use (GB/T8162-2008), fluid transportation use (GB/T8163-2018), etc., with materials including low carbon steel (such as 10 #, 20 #) and alloy steel (such as 16Mn). ‌
无缝钢管：分为结构用（GB/T8162-2008）、流体运输用（GB/T8163-2018）等，材料包括低碳钢（如 10#、20#）和合金钢（如 16Mn）。
Specifications and dimensions
规格与尺寸
Scaffold steel pipe: allowable deviation of outer diameter ± 0.5mm, negative deviation of wall thickness ≤ 0.36mm. ‌
脚手架钢管：允许外径偏差±0.5毫米，壁厚负偏差≤0.36毫米。
Seamless steel pipe: The outer diameter of hot-rolled pipe is ≥ 32mm, and the outer diameter of cold-rolled pipe can reach 6mm, with higher wall thickness accuracy. ‌
无缝钢管：热轧管外径≥32毫米，冷轧管外径可达6毫米，且壁厚精度更高。
Appearance and safety requirements
外观与安全要求
Surface: No rust (depth ≤ 0.5mm), pits (≤ 5mm), bends (≤ 3mm) or cracks. ‌
表面：无锈迹（深度≤0.5毫米）、坑洞（≤5毫米）、弯曲（≤3毫米）或裂纹。
Fasteners: Made of malleable iron, with a bearing capacity of ≥ 8kN for right angle fasteners, ≥ 8.5kN for rotary fasteners, and a bolt tightening torque of 40-65N · m. ‌
紧固件：由可锻铁制成，直角紧固件承载力≥为 8 千牛，旋转紧固件承载力为 8.5 千牛≥，螺栓紧固扭矩为 40-65 牛顿·m. ‌
Other standards  其他标准
Single weight: The maximum weight of scaffold steel pipes is ≤ 25.8kg, based on the safety limit for manual handling. ‌
单重：脚手架钢管的最大重量≤25.8公斤，基于手动搬运的安全限制。
Anti corrosion treatment: New steel pipes need to be coated with anti rust paint, and old steel pipes should be inspected for rust every year.
防腐处理：新钢管需要涂覆防锈漆，旧钢管每年都要检查是否有锈。