Hot Dip Galvanized Square Hollow Section Tubes
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Send your sizes and quantity on WhatsApp +971 56 227 5722 or through the quote request form, and you get a figure back with a lead time. Cut to length included, mill test certificates with the material, delivery to all seven emirates.
Hot dip galvanized square hollow section, also called HDG SHS, galvanized square tube or GI square pipe, is square steel tube protected by a thick zinc coating applied after fabrication of the tube. In the UAE climate, with coastal humidity, salt and sand, it is the standard choice for anything built to stay outside: fencing, gates, shade structures, solar frames and external steelwork. Seen Steel supplies hot dip galvanized SHS from 20 x 20 mm up to 300 x 300 mm, delivered to all seven emirates.
Sizes and weights
Weights are black steel weights calculated at 7.85 g/cm³, before galvanizing. Standard length is 6 m.
| Size (mm) | Wall thickness (mm) | Approx. black kg per metre |
|---|---|---|
| 20 x 20 | 1.5 / 2.0 | 0.87 / 1.13 |
| 25 x 25 | 1.5 / 2.0 | 1.11 / 1.44 |
| 40 x 40 | 2.0 / 3.0 | 2.39 / 3.49 |
| 50 x 50 | 2.0 / 3.0 / 4.0 | 3.01 / 4.43 / 5.78 |
| 60 x 60 | 3.0 / 4.0 | 5.37 / 7.03 |
| 75 x 75 | 3.0 / 4.0 / 5.0 | 6.78 / 8.92 / 10.99 |
| 80 x 80 | 3.0 / 4.0 | 7.25 / 9.55 |
| 100 x 100 | 3.0 / 4.0 / 5.0 / 6.0 | 9.14 / 12.06 / 14.91 / 17.71 |
| 120 x 120 | 4.0 / 5.0 / 6.0 | 14.57 / 18.05 / 21.48 |
| 150 x 150 | 5.0 / 6.0 / 8.0 | 22.77 / 27.13 / 35.67 |
| 200 x 200 | 6.0 / 8.0 | 36.55 / 48.23 |
| 250 x 250 | 8.0 / 10.0 | 60.79 / 75.36 |
| 300 x 300 | 10.0 | 91.06 |
For the formula and more sections, see the steel weight chart.
How much zinc: EN ISO 1461
Hot dip galvanizing to EN ISO 1461 sets a minimum average coating thickness by steel thickness. Because the tube is dipped, the zinc coats the inside as well as the outside.
| Steel thickness | Minimum mean coating | Approx. zinc per m² |
|---|---|---|
| Under 1.5 mm | 45 µm | 320 g/m² |
| 1.5 to 3 mm | 55 µm | 395 g/m² |
| 3 to 6 mm | 70 µm | 505 g/m² |
| Over 6 mm | 85 µm | 610 g/m² |
Zinc adds roughly 3 to 7 percent to the black steel weight, more on thin walled tube and less on heavy sections. Our guide to GI coating classes explains how this compares with pre-galvanized Z120 to Z275 material.
Hot dip galvanized or pre-galvanized tube
Two very different products are sold as galvanized tube in the UAE. Pre-galvanized (often called GI tube) is made from strip that was galvanized before the tube was formed, usually Z120 to Z275. The coating is thin, the weld seam and cut ends are bare, and the inside is often not protected. Hot dip galvanized tube is dipped in molten zinc after it is made, so the coating is several times thicker and covers the inside, the weld and every cut end. For external, coastal and structural work, hot dip galvanized is the one to specify.
Standards
- Tube: EN 10219 in S235JRH, S275J0H or S355J2H, or ASTM A500 Grade B or C
- Galvanizing: EN ISO 1461 or ASTM A123
For uncoated tube, see our mild steel square hollow sections. For rectangular profiles, see galvanized RHS.
Common applications
- Fencing, gates and boundary walls
- Handrails, guardrails and balustrades
- Shade structures, canopies and carports
- Solar panel mounting structures
- Scaffolding style frames and temporary works
- Coastal, marina and agricultural structures
Fabricating galvanized tube
Cutting and welding galvanized tube burns off the zinc at the joint. Repair every weld and cut with zinc rich paint, or better, fabricate in black steel and galvanize the finished frame. If you are building frames repeatedly, send us the drawing and we can advise which route is cheaper.
Cutting and delivery
We supply 6 m lengths or cut to your list. Deliveries go to workshops and sites across all seven emirates, including Al Quoz, Jebel Ali, Mussafah, Sajaa, Ajman Industrial and Al Hamra. Mill test certificates are supplied with the material.
Frequently asked questions
Is galvanized square tube the same as GI pipe?
In UAE usage, GI pipe or GI tube often means pre-galvanized tube. Hot dip galvanized tube has a much thicker coating. Always ask which one you are being quoted.
How long does hot dip galvanized steel last in the UAE?
It depends on exposure, but a hot dip coating typically lasts many times longer than paint alone, and far longer inland than on the coast. Thicker coatings last proportionally longer.
What is the weight of a 50 x 50 x 2 galvanized tube?
About 3.0 kg per metre in black steel, plus a few percent for the zinc.
Do you supply mill test certificates?
Yes, MTCs are issued with the material.
Send your galvanized square tube requirement through the steel quote request form or on WhatsApp at +971 56 227 5722.