What You Need To Know About Square Hollow Section
We use Square Hollow Section (SHS) to ensure a balance between functionality and strength in the mechanical and structural applications. With equal-sided SHS symmetry, the aesthetics are maintained and it also ensures economical joining alongside other important fabrication processes.
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SHS should be straight while linking to other flat surfaces. Slight edge preparation is required for welding and joining. This is best among other available structural sections for compression applications.
About Square Hollow Section
HSS or Hollow structural section is a metal profile with HCS (hollow cross-section). The term HSS is predominantly used in the U.S. and other countries where the engineering or construction terminology of the United States is being followed.
The hollow structural section members could be rectangular, circular, or square sections. However, there are also other shapes available, like elliptical. HSS is made of only structural steel.
Sometimes, people mistake HSS for hollow structural steel. Square and rectangular HSS are also known as box section or tube steel. A circular HSS is often called as ‘steel pipe’, but this isn’t true because the class and dimensions of a steel pipe are always different from HSS. The HSS corners are deeply rounded, with a radius that is two times the thickness of the wall. The thickness of the wall around the section is uniform.
HSS term is not used in the United Kingdom and other countries where British engineering or construction terminology is followed. Instead of HSS, they use SHS, RHS, and CHS, being square, rectangular, and circular hollow sections. Normally, such designations also relate to the metric sizes, so the tolerances and dimensions are a little different from the HSS.
Use of Square Hollow Section in Structures
HSS, especially square and rectangular sections are often used in the welding steel frames. They are used when the members under immense load from different directions. Circular and square HSS comes in extremely effective outlines for the several-axis loading because they come in uniform geometry with a couple of cross-sectional axes. Because of that, they form strength characteristics. HSS are great choices for the columns and also offer great resistance to the torsion.
HSS is also used as the beams. Though, I-beam or wide flange shapes are more effective structural shapes in various cases for such applications. However, HSS offers greater resistance to the lateral-torsional buckling.
Rectangular HSS has flat surfaces and it eases construction. Sometimes, they are given preference for architectural aesthetics. However, elliptical HSS is getting popular in the exposed structures because of aesthetics reasons.
Earlier, the HSS was normally available in the mild steel, like A500 grade B. But today, it is available commonly in the mild steel, like A500 grade C. The other available steel grades are A847, A1065, and the most recently approved HSS A1085.
SHS Manufacturing
The manufacturing process of a square hollow section is the same as the manufacturing process of a pipe. An evenly surfaced steel plate gets changed gradually in outline to the point where it becomes round and the edges of steel become weld-ready. After that, the plate edges are weld together that forms a mother tube. Different shaping stands are used for mother tubes during the manufacturing process to form round mother tubes (HSS) into final rectangular or square shapes.
Most of the American manufacturers prefer ASTM A1085 or ASTM A500 standards. Canadian manufacturers are using both CSA G40.21 and ASTM A500, while Europeans use EN 10210 hollow sections standards.
Filled HSS
To improve the robustness and fire rating, HSS is usually filled with concrete. After filling up HSS with concrete, it is called the Lally column. For instance, the barriers that you see around the parking areas are often the concrete-filled HSS. This is a cost-efficient way of improving bollard strength that ultimately assists in avoiding unappealing local denting.
Square Hollow Section Sizes/Dimensions
The square hollow section comes in different sizes and dimensions. Look at the following table:
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 |
In the above table, kg/m means kilograms per meter of section.
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Conclusion
SHS (square hollow section) is a popular steel tube type used to strengthen structures. The surface of SHS is flat and it is used because it is an economical way of welding and joining and also needs the least edge preparation. The available grades of SHS are JIS, GB, ASTM and EN.