Mild Steel Rectangular Hollow Section Tubes

Mild steel rectangular hollow section, known as RHS, rectangular tube or rectangular box section, is the go-to section when a member needs to be stiffer in one direction than the other. Turned on its edge it works like a light beam, which is why it is used so widely for purlins, lintels, rafters, trailer chassis and gate frames. Seen Steel supplies MS rectangular hollow sections from 40 x 20 mm up to 400 x 200 mm, cut to length and delivered to all seven emirates.

Sizes and weights

These are the rectangular tube sizes most often ordered in the UAE. Weights are calculated from the section geometry at 7.85 g/cm³ and ignore the corner radii, so real tube comes in slightly lighter. Use them for estimating and transport planning, and the mill certificate for invoicing.

Standard length is 6 m. A useful shortcut: a rectangular tube weighs the same per metre as a square tube with the same perimeter and wall, so 150 x 50 x 5 weighs the same as 100 x 100 x 5. For other sections and the formula, see the steel weight chart.

Why choose rectangular over square

For the same weight of steel, a rectangular tube placed with its long side vertical is considerably stiffer in bending than a square tube. A 150 x 50 section and a 100 x 100 section weigh the same, but the 150 x 50 carries more load across a span when it is stood on edge. That makes RHS the efficient choice for anything that spans: purlins, rails, lintels, stair stringers and beams in light frames. Square tube is the better choice for columns and posts, where load can come from any direction.

The flip side is orientation. Laid flat, the same rectangular tube is much weaker. Make sure the fabricator knows which way the section is meant to sit.

Standards and grades

Rectangular hollow sections for structural use are made to hollow section standards, not pipe standards. Pipe specifications such as ASTM A53 and A106 apply to round pipe and do not cover rectangular tube. The ones to look for on UAE drawings are:

• EN 10219, cold formed welded hollow sections, in S235JRH, S275J0H or S355J2H
• EN 10210, hot finished hollow sections
• ASTM A500, Grade B or C, for American specified projects
• JIS G3466, STKR400, the Japanese standard for rectangular and square tubes

If the drawing names a grade, supply that grade or get a substitution approved in writing. Our guide to steel grades explains how S275, S355, A36 and SS400 compare.

Mild steel or galvanized

Bare rectangular tube needs a paint or coating system for outdoor use anywhere in the UAE. For fencing, external frames, shade structures and coastal sites, hot dip galvanized hollow sections last far longer with little maintenance. For internal work and items painted after fabrication, mild steel is the economical option.

Common applications

• Roof purlins, rafters and side rails for light steel buildings
• Door and window lintels, frames and mezzanine joists
• Gate frames, fence rails and handrail systems
• Trailer chassis, truck bodies and container modifications
• Stair stringers, platforms and access structures
• Machinery bases, conveyor frames and racking

Cut to length and delivery

We supply full 6 m lengths or cut to your cutting list, so you do not pay to scrap offcuts. Deliveries go to workshops and sites across all seven emirates, from Al Quoz and Jebel Ali to Mussafah, Sajaa, Ajman Industrial and Al Hamra. Mill test certificates come with the material.

What to send for a quote

• Size and wall thickness, for example 100 x 50 x 4
• Standard and grade if your drawing specifies one
• Number of lengths, total metres, or your cutting list
• Mild steel or galvanized
• Delivery location

Frequently asked questions

What is the weight of 100 x 50 x 4 rectangular tube?
About 8.9 kg per metre, or roughly 53.5 kg for a 6 m length.

Is RHS stronger than SHS?
In one direction, yes. Stood on edge, a rectangular tube resists bending better than a square tube of the same weight. In the other direction it is weaker, so it suits beams and rails, while square tube suits columns. See our square hollow sections.

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

Is rectangular tube the same as box section?
Yes. RHS, rectangular tube, rectangular box section and rectangular hollow section all refer to the same product.

Do you also supply round pipe?
Yes, see our circular hollow section pipes.

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

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

Supply and delivery

Rectangular hollow section gets specified where the load runs one way and a square section would be wasting steel on the axis that does not need it. That makes RHS a section people order to a calculation rather than a habit, so the orientation matters as much as the size.

Who buys RHS from us

• Trailer, truck body and container fabricators building chassis members and floor bearers
• Steel contractors using RHS as purlins, side rails and lintels
• Signage and facade companies framing panels and light boxes
• Shelving and storage manufacturers where the beam depth has to clear a pallet
• Workshops building ramps, gantries and lifting frames

Getting the orientation right

A 100 x 50 and a 50 x 100 are the same section turned ninety degrees, and the difference in stiffness between the two is large. When you send a list, say which dimension is the depth in the direction of the load. It takes one line and it is the error that most often turns into a reorder.

Cutting and lengths

Supplied in 6 m and 12 m lengths, or cut to your list. For trailer and body work, where the same few lengths repeat across a build, cutting to size before delivery removes a whole step and most of the scrap.

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.