Hollow Structural Sections (HSS) are steel sections that are commonly used in construction for their high strength-to-weight ratio and aesthetic appeal. There are several types of HSS, including:

**Rectangular Hollow Sections (RHS):**These have a rectangular cross-section. They are commonly used in construction as columns, braces, and in truss work.**Square Hollow Sections (SHS):**These have a square cross-section. They are often used in structures that require a balanced load distribution, such as towers and bridges. They are also used in many aesthetic architectural applications due to their symmetrical shape.**Circular Hollow Sections (CHS):**These have a circular cross-section, also known as round Hollow Structural Sections. They are often used in structures that require rotational symmetry, such as signposts and railings. They also have good torsional rigidity and are used in applications where twisting loads may be present.

Each type of HSS has its own strengths and is more suitable for certain types of applications over others. The choice between RHS, SHS, and CHS will depend on factors such as the nature of the load, the direction of the load, aesthetic considerations, and the specific requirements of the project.

All types of HSS can be produced in a range of sizes and thicknesses, and they can be made from a variety of materials, although steel is the most common due to its high strength and durability. The specific properties of an HSS (such as its mechanical properties or chemical composition) will depend on the material from which it is made. Always refer to the manufacturer’s technical datasheet for exact specifications.

**Hot Finished Seamless (HFS)**: Material is heated and pierced to create a hollow tube, then further heated and stretched to the desired size and wall thickness. The tube is then cooled and cut to length. This process results in a tube with no welds or seams.**Cold Drawn Seamless (CDS)**: Similar to HFS, but the tube is further processed in a cold state, providing closer dimensional tolerances and a better surface finish.

**Electric Resistance Welded (ERW)**: The strip is rolled into a tube, and then the seam is welded using electric resistance.**Submerged Arc Welded (SAW)**: Similar to ERW, but the welding process is submerged under a flux.

**Low Carbon Steel**: Typically used in structural applications due to its high strength and ductility.**Medium Carbon Steel**: Offers a balance between strength and ductility, used in general-purpose applications.

**Low Alloy Steel**: Contains additional elements for improved strength and resistance to wear and temperature.**High Alloy Steel**: Contains a high percentage of alloying elements, providing superior strength and corrosion resistance.

**ASTM A500**: Standard for cold-formed welded and seamless carbon steel structural tubing.**ASTM A513**: Standard for electric resistance welded carbon and alloy steel mechanical tubing.**EN 10219**: European standard for cold formed welded structural hollow sections.

**Square Section**: Equal width and height, used in structural applications.**Rectangular Section**: Unequal width and height, used in a variety of applications where aesthetics or specific dimensions are important.

**Black (Self-Colored)**: No surface treatment.**Hot-Dipped Galvanized**: The pipe is dipped in a bath of molten zinc for corrosion resistance.**Electro-Galvanized**: Similar to hot-dipped, but the zinc coating is applied using an electrical current.**Powder Coated**: A dry powder is applied to the surface for color and corrosion resistance.

**Structural**: Used in construction and engineering where strength is paramount.**Mechanical**: Used in machinery and automotive applications where precision and strength are required.**Decorative**: Used in architectural and aesthetic applications where appearance is important.

Size mm |
kg/m |
Size mm |
kg/m |

20 x 20 x 2.0 | 1.12 | 20 x 20 x 2.5 | 1.35 |

25 x 25 x 1.5 | 1.06 | 25 x 25 x 2.0 | 1.43 |

25 X 25 X 2.5 | 1.74 | 25 X 25 X 3.0 | 2.04 |

30 X 30 X 2.0 | 1.68 | 30 X 30 X 2.5 | 2.14 |

30 X 30 X 3.0 | 2.51 | 40 x 40 x 1.5 | 1.81 |

40 x 40 x 2.0 | 2.31 | 40 x 40 x 2.5 | 2.92 |

40 x 40 x 3.0 | 3.45 | 40 x 40 x 4.0 | 4.46 |

40 x 40 x 5.0 | 5.40 | 50 x 50 x 1.5 | 2.28 |

50 x 50 x 2.0 | 2.93 | 50 x 50 x 2.5 | 3.71 |

50 x 50 x 3.0 | 4.39 | 50 x 50 x 4.0 | 5.72 |

50 x 50 x 5.0 | 6.97 | 60 x 60 x 3.0 | 5.34 |

60 x 60 x 4.0 | 6.97 | 60 x 60 x 5.0 | 8.54 |

60 x 60 x 6.0 | 9.45 | 70 x 70 x 3.0 | 6.28 |

70 x 70 x 3.6 | 7.46 | 70 x 70 x 5.0 | 10.11 |

70 x 70 x 6.3 | 12.50 | 70 x 70 x 8 | 15.30 |

75 x 75 x 3.0 | 7.07 | 80 x 80 x 3.0 | 7.22 |

80 x 80 x 3.6 | 8.59 | 80 x 80 x 5.0 | 11.70 |

80 x 80 x 6.0 | 13.90 | 90 x 90 x 3.0 | 8.01 |

90 x 90 x 3.6 | 9.72 | 90 x 90 x 5.0 | 13.30 |

90 x 90 x 6.0 | 15.76 | 90 x 90 x 8.0 | 20.40 |

100 x 100 x 3.0 | 8.96 | 100 x 100 x 4.0 | 12.00 |

100 x 100 x 5.0 | 14.80 | 100 x 100 x 5.0 | 14.80 |

100 x 100 x 6.0 | 16.19 | 100 x 100 x 8.0 | 22.90 |

100 x 100 x 10 | 27.90 | 120 x 120 x 5 | 18.00 |

120 x 120 x 6.0 | 21.30 | 120 X 120 X 6.3 | 22.30 |

120 x 120 x 8.0 | 27.90 | 120 x 120 x 10 | 34.20 |

120 X 120 X 12 | 35.8 | 120 X 120 X 12.5 | 41.60 |

140 X 140 X 5.0 | 21.10 | 140 X 140 X 6.3 | 26.30 |

140 X 140 X 8 | 32.90 | 140 X 140 X 10 | 40.40 |

140 X 140 X 12.5 | 49.50 | 150 X 150 X 5.0 | 22.70 |

150 X 150 X 6.3 | 28.30 | 150 X 150 X 8.0 | 35.40 |

150 X 150 X 10 | 43.60 | 150 X 150 X 12.5 | 53.40 |

150 X 150 X 16 | 66.40 | 150 X 150 X 16 | 66.40 |

180 X 180 X 5 | 27.40 | 180 X 180 X 6.3 | 34.20 |

180 X 180 X 8 | 43.00 | 180 X 180 X 10 | 53.00 |

180 X 180 X 12.5 | 65.20 | 180 X 180 X 16 | 81.40 |

200 X 200 X 5 | 30.50 | 200 X 200 X 6 | 35.8 |

200 x 200 x 6.3 | 38.2 | 200 x 200 x 8 | 48.00 |

200 x 200 x 10 | 59.30 | 200 x 200 x 12.5 | 73.00 |

200 x 200 x 16 | 91.50 | 250 x 250 x 6.3 | 48.10 |

250 x 250 x 8 | 60.50 | 250 x 250 x 10 | 75.00 |

250 x 250 x 12.5 | 92.60 | 250 x 250 x 16 | 117.00 |

300 x 300 x 6.3 | 57.90 | 300 x 300 x 8 | 73.10 |

300 x 300 x 10 | 57.90 | 300 x 300 x 8 | 90.70 |

300 x 300 x 12.5 | 112.00 | 300 x 300 x 16 | 142.00 |

350 x 350 x 8 | 85.70 | 350 x 350 x 10 | 106.00 |

350 x 350 x 12.5 | 132.00 | 350 x 350 x 16 | 167.00 |

400 x 400 x 10 | 122.00 | 400 x 400 x 12 | 141.00 |

400 x 400 x 12.5mm | 152.00 | 400 x 400 x 16 | 192 |