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Radius Square tube

A popular variation on square steel tubing, Timeless’s unique radius square tube boasts a beautifully contoured shape. The refined design looks and feels better than square tube and conventional box tubing, making it an excellent alternative to standard square shaped tube.

William Jets Tenders with grip handles made from radius square super marine stainless steel tubing from Timeless
  • Blended radiused corners and a slight convex side provide impressive strength integrity
  • Elegant alternative to standard box section tubing
  • Typically used for baluster railings, stanchion posts, grab rails and furniture
  • Lighter and more cost-effective than solid bars
  • Symmetrical profile enables sweeping bends to be made with relative ease

9 existing sizes of stainless steel radius square tube and multiple wall thicknesses

From 17×17×1.5mm to 88×88×2mm.

Most popular sizes

  • 17 × 17 × 1.5mm
  • 34 × 34 × 1.5mm
  • 45 × 45 × 1.5mm
  • 45 × 45 × 2mm
Multiple sizes of stainless steel radiused square tubing with a mirrored finish

Smooth, 'softened' corners for decorative applications and easy maintenance

Due to its appealing softened corners and the range of available sizes, this tubing is ideal for balustrades and handrails. The two largest tube sizes are suitable for newel posts (commonly known as staircase spindles). Our engineers have formed this tubing from ‘marine grade’ 316L stainless steel to be used as grab rails on luxury tender boats; it is both elegant and ergonomically viable as an important safety feature onboard world-class sea-faring craft.

Stainless steel, aluminium, titanium, or copper-based square tubing

We can form this specialist square metal tubing from our full metal selection. Stainless steel 304L and 316L are our most popular materials due to their high durability and range of finishes, but we can also make them from titanium, aluminium or copper. Contact us today and we can talk you through the different metals and finishes available and the other fabrication services we offer.

Find out more
stainless steel in a mill finish
Stainless Steel
aluminium in a mill finish
brass in a mill finish
cupronickel in a mill finish

Structurally strong steel square tubing

Our stainless steel radius square tubing has impressive strength integrity. Timeless’s robust deflection tests show that when tested on the flat side (the ‘flush’), the radius square tube is 54% stronger in terms of its deflection capacity than its round tube equivalent. Its strength, coupled with its symmetry, means that our radius square steel tube is an ideal candidate for bending, should you require a large radius bend for your application.

View Deflection Test
stainless steel mirror polished radius square tubing being stress tested under a hydraulic arm

Rectangular tube with elegant rounded edges

Boasting gently contoured edges, this unique rectangular shaped tube is a variation on our much-loved radius square tube. A recent addition to the Timeless tube family, this exciting profile can be made from stainless steel, brass or aluminium. If you are interested in this new rectangular tube then phone us to discuss your application and the size you require: our engineers love developing new sizes.

Ask us about rectangular tubing

Fabrication services for radius square tube

If you want to use radius square tubing in your project, contact us for specialist tubing fabrication services. We offer a wide range of fabrication services that use radius square tubes.

Find out more about our Fabrication services


Stainless steel and aluminium 5083 radius square tube profiles are sold in lengths of 5.8m (the manufacturing process reduces the standard 6m length by 0.2 metres).

Can’t see the tube sizes you need in the table? Contact us about custom-sized tubing; we may able to fabricate a new size to meet your project requirements. Or download our brochure, which contains sizing information for existing aluminium and brass tubing too, as well as all stainless steel sizes.


If required, we can find out wall thickness tolerances from our metal suppliers. Typically the tolerance levels of wall thickness are extremely minimal and any small variations in thickness do not affect further fabrication or the end application. However, it is important to tell us if the tolerance is critical to the application before you place an order. For example, if the shaped tubing component needs to go inside another component, or if the tubing has to house a component, any variation in wall thickness could be critical.

The image above shows how dimensions are detailed
(for example, 17mm x 17mm x 1.5mm)

Sizes given below are for stainless steel.

Tube Sizes
17mm x 17mm
23mm x 23mm
28mm x 28mm
34mm x 34mm
45mm x 45mm
66mm x 66mm
88mm x 88mm
wall thickness
wall thickness
Scroll to view Sizes
Show Imperial Sizes
Download Size Chart PDF

Applications for radius square tube

  • Staircases
  • Balusters
  • Newels
  • Balconies
  • Radiators
  • Door handles
  • Street signs
  • Queue management systems
  • Metal stair nosing
  • Food and drink manufacturing equipment

Not based in the U.K? Find out about our international shipping services

If you need radius square tubing but you're not based in the UK, then speak to us about shipping options. Clients from across the globe regularly come to us for our unique shaped tubing and specialist tube fabrication. We can ship our tube to North America and Europe in as little as 48 hours. Our freight team will work to meet your transit times and budget; get in touch to discuss shipping options.

Find out more about international shipping
International shipping
Timeless specialists looking over technical drawings for a tubing project

Need help finding the right size and tube shape?

Speak with one of our tube specialists to find out how best to integrate shaped tubing into your project. We can give you information on the best profile, metal, finish and dimensions for your application.

Talk to a specialist

Contact us for expert advice, quotes and free samples.


We can develop new sizes

Don't see a size you need? Just specify the size you require in your message.

We can develop new sizes

Don't see a size you need? Just specify the size you require in your message.

We can develop new sizes

Don't see a size you need? Just specify the size you require in your message.

We can develop new sizes

Don't see a size you need? Just specify the size you require in your message.

We can develop new sizes

Don't see a size you need? Just specify the size you require in your message.

We can develop new sizes

Don't see a size you need? Just specify the size you require in your message.

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Need help finding the right tube?

Talk to a specialist and find the right tube for your project.

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