Steel and Structural Pipes

Grid structure is composed of comparable grids or small dimension units. This structural pipe is often used in roof structure. Our clients are able to provide high-quality seamless steel tube for lattice framed structure firm. This product is applicable to large, medium or small span roof equipment.

EOI structural pipes are extensively used in stadium, club, exhibition hall, theater, station waiting hall, airport, warehouse, workshop and other public buildings. This seamless steel tube can be also applied in various kinds of special structures with different functions to make buildings more solid and exceptional.


  1. This structural pipe always makes the lattice framed structure have big space stiffness, integrity and strong earthquake-resist capacity. It additionally be withstand the negative influence of uneven settlement of bottom.
  2. JST seamless steel tube used for grid structure is of sunshine weight and uses less steel.
  3. It's also applicable to associated with architecture in planar form, such as rectangular, round, circular sector or polygon shape.
  4. Frequently use Q235 or Q345 steel to provide structural pipes. We even adopt small specifications of rod piece section to construct big span constructions. Grid structure can make full use with the strength of seamless steel tubes and save steel.
  5. Lattice framed structure along with rod pieces have uniform specifications, the actual pipes are befitting industrialized production. You won't favorable conditions and guarantee for increasing the engineering progress.

Quality Standards of Structural Pipe

  1. Economic downturn of grid structured seamless steel tubes must be as outlined by the requirements of GB50205-2001 Steel Structure Construction and Inspection Rules.
  2. Steel plate should be welded in full penetration. When δ is equal to or more than 8 mm, we all do ultrasonic inspection and checkout for the welding seam. The inspection ratio is 20 percent from the length of welding seam. If structural pipe complies with GB11345-89B III class inspection standard, end up being qualified. (δ means the thickness of steel plate.)
  3. JST often uses Q345 and Q235 grades of seamless steel tubes to produce lattice framed design. Chemical composition and mechanical property should respectively consider GB/T1591-94 low alloy and high strength structural steel and GB700-88 carbon structural steel.
  4. Our structural pipes are produced from high-quality gold. Before entering warehouse, inspectors will check the quality certificate and check each indicator. Once they ensure that seamless steel tubes are qualified in accordance with relevant standards, the products could be put in ram.

Parameters Data of Structural Pipe

Mechanical and Processing Properties Parameters


  1. When do drawing and bending test, ought to select transverse steel test sample. The steel with the width of under 600 mm, we choose longitudinal test piece.
  2. The elongation of seamless steel tube is allowed to be reduced by ±1% than the values in the above table.
  3. The elongation of Q345 grade steel plate with the thickness of 35 mm can be reduced by ±1%.
  4. For that round or square steel with one side length or diameter more than 50 mm to 100 mm, the elongation can be reduced by ±1% versus the values in previously mentioned table.
  5. The top limit value of tensile strength of wide steel strips will not be treated as the delivery condition.
  6. Grade A steel should be done with bending test. For other grades of steel, if suppliers can promise the bending test result complies the brand new requirements in previously mentioned table, the test can be held back.
  7. Effect force and test temperature in Charpy (V-notch) impact test should comply but now requirements on the table. Impact force value is calculated by the arithmetic mean value of three samples from a group. It allows one sample value to be underneath the specified value associated with table, but for 70% of the wanted value.
  8. Many of us adopt small size samples to do impact test (5 mm × 10 mm × 55 mm), the test result should not really less than 50% of the specified value.
  9. Q460 and various grades of D and E steel generally do not supply profile steel and steel bar.

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