LONG PRODUCTS -Flat /Square bar

Grade: This section lists various international steel grades:

• Q235/Q275/Q345: Chinese National Standards (GB) for carbon structural steel, indicating minimum yield strengths of 235 MPa, 275 MPa, and 345 MPa respectively.
• SS400: Japanese Industrial Standard (JIS) for general structural steel, with a tensile strength of 400-510 MPa.
• A36/A572 GR.50: American Society for Testing and Materials (ASTM) standards. A36 is a common carbon structural steel, while A572 GR.50 is a high-strength low-alloy structural steel with a minimum yield strength of 50 ksi (approximately 345 MPa).
• S235JR/S275JR/S355JR: European Standards (EN) for structural steel. The numbers (235, 275, 355) represent the minimum yield strength in MPa, and "JR" indicates that the steel has a minimum impact energy value at room temperature.
• Q235/Q275: (Repeated, perhaps emphasizing these common grades for certain products).
• 3SP/5SP: These are designations for carbon steel used in rebar or some structural applications, often indicating weldability and deoxidation practices. "SP" stands for "semi-killed." For instance, they might relate to older Russian (GOST) or Chinese standards for reinforcing bars (e.g., A3SP, A5SP).

Size 1:

• 16-300mm*1.5-15mm*5.5-6.0mm: This notation is a bit unusual.
  • 16-300mm: This likely refers to the outer dimension (diameter for circular, or side length for square/rectangular).
  • 1.5-15mm: This would typically be the wall thickness range.
  • 5.5-6.0mm: This third range is peculiar if the previous two define a pipe or HSS. It might be an error, a typo, or refer to an additional property or a specific type of welding seam/flange, but without further context, it's difficult to definitively interpret. If it's a pipe, the format usually is Outer Diameter x Wall Thickness. If it's HSS, it's usually (Side 1) x (Side 2) x Wall Thickness.

Size 2:

• 9*9—200*200: This strongly suggests square hollow structural sections (HSS).
  • 9*9: Indicates a 9mm x 9mm square section (likely outer dimensions). This is a very small size for HSS, but possible for thin-walled applications.
  • 200*200: Indicates a 200mm x 200mm square section. This notation usually implies that the thickness would be associated with each specific size within this range, or there's a separate general thickness range.