1. Dimensional Tolerance: This refers to the allowable dimensional deviation range during the production of shaped steel pipes. The size of the dimensional tolerance directly affects the quality and performance of the shaped steel pipe. Generally, the smaller the dimensional tolerance, the higher the quality of the shaped steel pipe.
2. Appearance Quality: This refers to the absence of obvious defects on the surface of the shaped steel pipe, such as cracks, inclusions, and rust. Good appearance quality not only improves the aesthetics of the product but also reduces problems during subsequent processing and use.
3. Mechanical Properties: This refers to the good strength, toughness, and hardness of the shaped steel pipe. The levels of these properties directly determine the safety and reliability of the shaped steel pipe during use.
4. Chemical Composition: This refers to the content of each element in the shaped steel pipe meeting specific standard requirements. A reasonable chemical composition not only ensures that the performance indicators of the shaped steel pipe meet the requirements but also improves its corrosion resistance and wear resistance.

Regarding the classification of special-shaped pipes:
https://www.chinasteelmarket.com/feature-pages/featureinfo/FEATURE%7C-The-Knowledge-Summary-of-Seamless,-Welded-Steel-Pipes,-Stainless-Steel-Pipes,-and-Special-shaped-Steel-Pipes_1166.html

Answers

• 
  What is the standard thickness of the anti-corrosion coating for anti-corrosion steel pipes? 22/12/2025 15:29:52
• 
  What are the standards and specifications for shaped steel pipes? 22/12/2025 06:17:44
• 
  What is the difference between Q235b seamless steel pipe and Q235d seamless steel pipe? 19/12/2025 13:32:35
• 
  What are the differences between DDP and FOB. which method is more convenient and less risky for us buyers? 18/12/2025 01:31:09
• 
  What are the different types of galvanizing? 17/12/2025 08:18:39