Testing the added strength of ZX profile

Knowledge is the accumulation facts, information, and skills acquired through experience or education”.

Accumulation of facts…

For many years we have known that our shallow ZX adds strength to Aluzinc material when used either as flat sheets or when rolled for use as insulation jacketing/cladding or ductwork.

To further expand our existing knowledge, earlier this year we undertook testing to further understand the difference made to various gauges when our ZX, PetrochemClad and Stucco profiles are added.

Some of the results where as we expected whilst other results came as a surprise to us even after 30yrs of selling Aluzinc products into the Petrochemical and HEVAC industries.


First we tested flat sheets of our most commonly supplied materials – 0.9 and 0.7mm un-profiled with 0.7, 0.5 and 0.4mm ZX profile, 0.7mm Stucco finish and 0.6 PetrochemClad.

Secondly we tested crush strengths of the similar gauges when rolled to tubes of various diameters and lengths. PetrochemClad was only tested as flatsheet.


As expected our ZX profile (which we roll ‘in-house’ from our stock material – creating sixty-six, one millimeter stiffening ribs per meter with no loss of over all coverage) added strength to each gauge – with even narrow stripes (300mm) giving at least 3 x the strength against the same gauge of un-profiled material.

When used as full width sheets (1mtr) the ZX profile proved even more impressive at over 5 x stronger – fact a piece of 0.4 ZX profile will take more load than 0.7 un-profiled sheet, potentially allowing savings in both weight and costs!

Additionally we found that the ZX profile performed better compared with un-profiled material the larger the diameter of tube we tested.

More than twice the strength, half the thickness, in an independant test an insulated pipe with Aluzinc fitted with end caps to the correct specification, clad in 0.4mm thick Petrochem Dobelshield/Stucco finish with our Petrochem ZX® profile was hardly even dented when pressure was applied equivalent to someone weighing twenty two stone (139.7 kg) standing on it. Whilst the same test showed that 0.7mm thick aluminium over a correctly insulated pipe with end caps, was very badly damaged when pressure was applied equivalent to an eleven and a half stone (73 kg) person standing on it – not only ruining its appearance but also its thermal efficiency.

Whilst still being as easy to bend, fold, guillotine or cut by hand as conventional material – the shallow ZX profiled proved easier to handle during the manufacture of tubes/pipe cladding etc, retaining it’s shape better than conventional un-profile material, with any potential the use of thinner gauge material being yet another added benefit.

Stucco finish – our testing showed a very slight increase in strength when used both as flat sheet and in a tube form, we therefore concluded that this finish is more of an aesthetic choice rather than a structural one.

PetrochemClad profile – rolled in house this profile has been supplied for use as cladding on tanks and vessels for many years. Testing showed just how much strength this 10mm profile adds along its length, whilst still retaining the ability to be curved around small diameters across its width if required – a 1mtr length was loaded to 120kg with minimal deflection and showed zero permanent deformation.


BS 5970:1992 26.6.4 advises not to use aluminium sheet in areas of potential mechanical damage.

BS 5970:1992 26.6.4 advises that “Aluminium, being relatively soft, should not be used for protection in areas where it is likely to be exposed to substantial mechanical damage, particularly when applied over flexible insulating material”



If you require detailed facts and figures from our testing please contact philip.lancaster@ssab.com