Mild Steel Square Hollow Section Tubes

Mild steel square hollow section, also called SHS, square tube or square box section, is one of the most used sections in UAE fabrication. It carries load equally well in both directions, welds cleanly, and gives a neat square profile for frames, columns, gates and structures. Seen Steel supplies MS square hollow sections from 20 x 20 mm up to 400 x 400 mm, cut to length and delivered across all seven emirates.

Sizes and weights

The table covers the sizes most often ordered in the UAE. Weights are calculated from the section geometry at 7.85 g/cm³. They ignore the corner radii, so actual tube runs two to four per cent lighter, which is fine for estimating a load. For invoicing, go by the mill certificate.

Standard length is 6 m. Other sizes and wall thicknesses within the 20 x 20 to 400 x 400 range are available on request. For the formula behind these figures and weights for other sections, see the steel weight chart.

Standards and grades

Structural square hollow sections are made to their own standards, separate from round pipe. The ones you will see on UAE drawings:

• EN 10219, cold formed welded hollow sections, in grades S235JRH, S275J0H and S355J2H. This is the most common specification on consultant drawings.
• EN 10210, hot finished hollow sections, used where the specification asks for hot finished rather than cold formed tube.
• ASTM A500, Grade B or C, common on American specified projects.
• JIS G3466, STKR400, the Japanese standard for rectangular and square tubes.

For general fabrication, any of these in the lower grade is suitable. For structural work, supply to whatever the drawing names. If your drawing says S355J2H, an S235 tube is not a substitute. Our guide to steel grades explains what the numbers and suffixes mean.

Cold formed or hot finished

Most square tube in the UAE market is cold formed: strip is rolled into a round tube, welded, then shaped square. It is economical and fine for the great majority of work. Hot finished tube is formed or reheated at high temperature, giving tighter corners and more uniform properties, and is specified for some heavy structural and dynamic load applications. If your specification does not say, cold formed is almost always what is intended.

Mild steel or galvanized

Bare mild steel square tube must be painted or coated for any outdoor use in the UAE. Coastal humidity will rust it within weeks. For external frames, fencing, canopies and anything near the sea, hot dip galvanized hollow sections are usually the better choice. For internal frames, furniture and items that will be painted after fabrication, plain mild steel is the economical option.

Common applications

• Building columns, portal frames and mezzanine structures
• Gates, fencing posts, railings and balustrades
• Canopies, sheds, carports and shade structures
• Machinery frames, bases and skids
• Furniture, shelving and display frames
• Trailer and vehicle body frames

Cut to length and delivery

We supply full 6 m lengths or cut to your list, so you are not paying for offcuts you will scrap. Deliveries go to fabrication yards and sites across all seven emirates, including Al Quoz, Jebel Ali, Mussafah, Sajaa and Al Hamra. Mill test certificates are supplied with the material.

What to send for a quote

• Size and wall thickness, for example 100 x 100 x 4
• Standard and grade if your drawing specifies one
• Quantity in lengths or total metres, or your cutting list
• Mild steel or galvanized
• Delivery location

Frequently asked questions

What is the difference between SHS and RHS?
SHS is square, with equal sides. RHS is rectangular, with one side longer than the other, which makes it stiffer in one direction. See our rectangular hollow sections.

What is the weight of 100 x 100 x 4 square tube?
About 12 kg per metre, or roughly 72 kg for a 6 m length.

What is the standard length?
6 metres. We can cut to your lengths before delivery.

Is square tube the same as box section?
Yes. Square tube, square box section, SHS and square hollow section are all names for the same product.

Do you supply mill test certificates?
Yes, MTCs are issued with the material.

Send your square hollow section requirement through the steel quote request form or on WhatsApp at +971 56 227 5722.

Supply and delivery

Square hollow section is the section most workshops get through fastest, so it is usually bought on a standing list rather than job by job. Tell us the sizes and thicknesses you repeat and reorders get priced against that list instead of quoted from scratch each time.

Who buys SHS from us

• Fit out and interiors contractors framing partitions, ceilings and shopfronts in the lighter sizes
• Fabricators building mezzanines, racking, platforms and machine frames
• Fencing, gate and canopy makers working in 40 x 40 through 100 x 100
• Furniture and shelving manufacturers buying consistent wall thickness for repeat runs
• Structural contractors using the heavier sizes as columns and truss members

Cutting and lengths

Standard lengths are 6 m and 12 m. Send a cutting list instead of a length count and the material arrives cut, which takes the sawing out of your shop and means you are not paying for the drop. On mixed lists the sizes get nested so the offcut is kept down, and that normally shows up as a lower price rather than a lower weight.

Specifying thickness

The single most common problem on an SHS enquiry is the wall thickness being left out or assumed. A 50 x 50 x 2 and a 50 x 50 x 3 look identical on a drawing note and differ by about half the weight again. State the thickness, and if the section is structural rather than decorative, state the grade with it.

Where we deliver

Deliveries run to every emirate: Dubai, Abu Dhabi, Sharjah, Ajman, Ras Al Khaimah, Fujairah, Umm Al Quwain. Site and workshop deliveries are both standard.

To price a list, send it through the steel quote request form or on WhatsApp at +971 56 227 5722. The full product list shows everything we carry.