Answers

• 
  Hi, I'm sourcing steel rebar, HRB400 grade. Diameter 8mm, 12mm, 16mm, length 12 meters. Need 200 to 500 metric tonnes FOB China. What's your rock-bottom price, delivery time, and can you send samples?
• 
  What's the difference between wire rod and rebar?

  Appearance
  Wire Rod: Smooth like noodles, usually less than 10mm in diameter, transported in coils, occasionally with a slight oxide scale on the surface.
  Rebar: A tough guy with barbs all over, with regularly raised horizontal and vertical ribs on the surface, mostly over 12mm in diameter, stored in straight strips.
  
  Performance
  Flexibility: Wire rod can be easily bent 360 degrees, suitable for deep processing; rebar is more likely to break than bend, maintaining a straight shape.
  Strength: Rebar has higher grip strength due to its surface texture, as stable as a rock in concrete; wire rod prioritizes ductility.
  Processing Method: Wire rod is often drawn into thinner wires, while rebar is mostly cut directly for use.

  
  
• 
  What is the typical hardness of steel pipes?

  The hardness of steel pipes is one of the important indicators for measuring their quality and performance. The hardness value directly affects the wear resistance, compressive strength, and service life of steel pipes.
  
  The hardness of steel pipes is generally measured by three hardness indices: Brinell, Rockwell, and Vickers. The specific hardness value varies depending on the type of steel and the manufacturing process. These indices are obtained through different testing methods and can comprehensively reflect the hardness characteristics of steel pipes. Generally speaking, the hardness value of steel pipes ranges from 30 to 80.
  Different types of steel pipes, such as casing steel and precision seamless steel pipes, have different hardness values. The hardness of casing steel is usually between 100 and 180, while the hardness of precision seamless steel pipes is between 80 and 120.
  Galvanized steel pipes have advantages in corrosion resistance and relatively high hardness. Typically, the hardness value of galvanized steel pipes is between 70 and 90, which meets the needs of general engineering applications.
  Seamless steel pipe is a common type of steel pipe with a relatively moderate hardness value. Generally speaking, the hardness of seamless steel pipes is between 30 and 50, making them suitable for a variety of engineering fields.