Square

Square tubes, also known as carbon fiber box sections, are optimised for high-performance strength and stiffness. With in-built radiused corners and flat sides, they are ideal for building support systems, lightweight frames and structures.

Enquire nowFrequently asked questions

Available carbon fiber box section sizes

If you've got an idea for square carbon tubing and know your specifications, choose your specs from the table below and get in touch.

About our products
  • Wall thickness will depend on individual requirements.
  • Corner radius will increase with wall thickness.
  • Standard walls range from 1.4 - 6.0mm; a price range (per metre) is shown for those thicknesses
  • Minimum order is $400. Some over-run stock tubes can be ordered in smaller amounts and are available in specific sizes (quantities available vary constantly).
  • Wall thicknesses above 6.0mm or alternative laminate and carbon fiber orientations can be custom-ordered.

All  Round Carbon Fiber Tubes

Product Dimension values
Round
Oval
Square
Rectangular
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Surface Finishes

Designed to make your composites corrosion resistant, UV protection and aesthetically pleasing, C-Tech provides finishes sustaining the long-term appearance of composite products.

Standard

Unidirectional or Cloth Finish

Glossy, unidirectional (spiral wound effect), cloth (woven or twill-weave) effect.

Clearcoat

Unidirectional or Cloth Finish

Smooth, clear and glossy cloth or uni finish.

Sanded

Unidirectional or Cloth Finish

Sanded finish ready for painting or gluing, cloth or uni option.

Peel-ply

Unidirectional or Cloth Finish

Textured finish designed as a gluing surface. It can be used inside tubes to create a gluing surface in areas that are hard to sand. This finish also provides a good grip on tubes either cloth or uni.

Painted

Unidirectional or Cloth Finish (UV Resistant)

Sanded and painted, giving a high gloss and the best UV protective coating and a high quality finish. We can offer any colour that is commercially available for spray painting.

Carbon Surface Finishes

Designed to make your composites corrosion resistant, UV protection and aesthetically pleasing, C-Tech provides finishes sustaining the long-term appearance of composite products.

Pre-preg

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S-Glass

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Standard, high and ultra-high modulus carbon fibers

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Carbon fiber

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Kevlar

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Metals and alloys including titanium printed components

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E-Glass

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Epoxy and Phenolic resin systems

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Core materials including honeycombs and foam

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Trusted carbon fiber suppliers to 1,000+ companies worldwide

Square tubes engineered for maximum strength and stiffness, or to satisfy application specific engineering parameters.

We specialise in making square tubes using pre-preg carbon fibre with epoxy resin and have a large range of tooling available. Therefor our Laminated from prepreg carbon fibres and epoxy resin, our square tubes are made for applications requiring high strength and rigidity.

  • High-tensile and torsional strength tolow-weight ratio
  • Excellent fatigue resistance
  • Dimensional stability
  • Easy to use in a variety of applications

See why ambitious companies around the world
partner with C-Tech

"Coming from our One Design Sailing background, we know that C-Tech deliver both quality and precision and as passionate sailors themselves, you are going to get ideas and contribution to a better end product."

Andy Robertson,
Kaizen Owner
KAIZEN

"We are a customer of C-Tech battens on Kaizen and had heard about some of their Americas Cup work, so when we came to build a new keel we put C-Tech on the list to approach. Coming from our One Design Sailing background we know that C-Tech deliver both quality and precision and as passionate sailors themselves, you are going to get ideas and contribution to a better end product."

Andy Robertson
Kaizen Owner
MARINE

“Oceania Aviation approached C-Tech in order to find a solution for the manufacture of carbon fibre spray booms for our AS350 Spray systems. The team came up with tapered hollow booms that fitted our brief perfectly, and we have now been using their manufacturing services for a number of years. The quality and service provided by C-Tech’s engineering staff is always of a high standard and they are a great team to work with.”

Tony Van Tiel
Oceania Aviation
AUTOMOTIVE

"C-Tech have really stepped our programme up another level this year, contributing greatly to getting our car down 20kg on last season! Their carbon is second to none in terms of both looks and strength! It has held up flawlessly to a lot of abuse while running on tracks with both rocks and large clumps of dirt. The perfect option to step up your race programme next season!"

Ryan Barry
Ryan Barry Racing
AVIATION

"The team came up with tapered hollow booms that fitted our brief perfectly, and we’ve now been using their manufacturing services for a number of years. The quality and service provided by C-Tech’s engineering staff are always of a high standard, and they are a great team to work with"

Tony van Tiel
Oceania Aviation
MARINE

"Working with C-Tech was a pleasure, they were consistently helpful, professional, and went the extra mile to make sure the project was a success"

Craig Stewart, Marine Physicist
NIWA
OTHER

"C-Tech's extensive experience and up-to-the-minute knowledge of everything composites has been invaluable to Wing in development of all-new manufacturing techniques. And their strong relationships with suppliers brings access to customised materials solutions that otherwise couldn't have contemplated"

Mike Palmer
Wing Acoustics
FILM

"We approached C-Tech with a unique design challenge to fabricate the structure of a kinetic interactive installation. The 18m long object needed to be lightweight and deployable for easy transport, while featuring a cantilever of 12m. The highly competent team at C-Tech was absolutely great to work with and delivered an impeccable solution."

Associate Professor Uwe Rieger
Lightscale - Head arc/ sec Lab
MARINE

"C-Tech's flexibility in design and build, combined with a willingness to collaborate on ideas, helped in producing the best components for our needs, giving us the best results"

Rig Construction Coordinator
Emirates Team New Zealand
MARINE

"Working with C-Tech for the past year has been an absolute joy. In a development class like the Moth, adapting quickly to the latest developments is absolutely essential to stay on top of the fleet and C-Tech has constantly been looking for new ways to get every single bit of performance out of the boat"

Nicolai Jacobsen
MARINE

"C-Tech have done an awesome job. We raced the state title on the weekend and the boat felt fast, getting a 5th, 1st and 3rd". Not bad considering I put the mast on the boat on Thursday and finished building the main Thursday night."

Scott Beeby
MARINE

"I used the new mast for the first time today with a Wavelength sail, the same sail I have been using. I just can’t get over how different the boat feels. I can’t tell you what the mast was doing that was different but it just felt good. Very happy. I’ll say it again the C Tech masts are just so superior over anything else."

Paul Cohen
MARINE

"I'm really impressed with the mast and sail combination. I do feel this mast suits the sail even better than the old mast. The bend is incredibly even for/aft and stiffer sideways but still an even bend. Just massive steps forward. The pressure in the main sheet is impressive. The sail shape is bloody wonderful. Very even break all along the luff, top of sail opens up perfectly in a puff while the bottom half remains with excellent closure/ return in the leech. She just wants to accelerate forward."

Geoff Fisher
MARINE

"The boat is going well in any conditions, which is great: we are super-fast with no wind, it is a true lake racer! But we also handled steady 25 knots going upwind with good speed. To beat the football team it needs above 12 knots of wind and foils, lets see next year."

Thomas Jundt
QFX
MARINE

"It has been a pleasure to work with C-Tech on this project - We are happy to have them as partners"

Michi Aeppli
Quant Boats
MARINE

"We've had our C-Tech SnuffAir for 12 months now and have used it flawlessly. It's even better than I expected actually, this is a massive sail and personally I don't think you could beat this."

Dougall Love
ROMANZA
MARINE

"It has been a game changer switching to FlexiFurls. They have given us true race performance in our furling sails. Also the service has been tops, so really happy all around."

Peter Homberg
MARINE

"We have used your product for many years and you know we call your battens a bit of a magic wand. They are a tool, but are hidden within the sail and you don't see them. Just like there are so many bad tools out there, there are also many bad battens. C-Tech battens are the tool that can actually make a bad sail look better, and make a good sail look great."

Christen
North Sails
MARINE

"WOW! When the order arrived not just on time but... ahead of time!"

Don Manning
Sailability
MARINE

"Slick building time and slick delivery."

John Butcher
MARINE

"The reassurance I've had in dealing with Tim makes me feel like I'm in very good hands. And because of service and guidance I decided early on to proceed with commissioning a new boom and spinnaker pole also to go with the mast."

Travis Tubman
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Pricing & Shipping

Pricing
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Terms of Delivery

Frequently asked questions

How is the diameter of your tubes measured?
Does a square tube have square corners?
How accurate is the internal/external size and shape?
Are square tubes stiffer/stronger than round tubes?
What finish options do you offer for your tubes?

Talk to us about your next project

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