Pre-galvanised tubes have excellent corrosive resistance where exposure to the outside elements is common. These tubes are formed from heavy duty zinc coated steel strips (pre-galvanised) and then subsequently joined together via high frequency welding. The external weld zone is then arc-sprayed creating a fully galvanised tube both inside and out.
Pre-galvanised tubes are tough and durable, yet they offer bending and forming capabilities after their manufacture.
High tensile grades are common and used where strength and weight are important factors. Light weight structures for both construction and horticultural industries use products of this type. The directive is to procure a tube suitable to build enclosures where strength and weight are paramount yet priced competitively. Pre-galvanised tubes are proving ever popular for an increasing number of applications.
Normally all grades of galvanised supplied will be chemically passivated. Chemical passivation protects against the effects of humidity and thereby reduces the risk of white rust formation during shipment and storage.
Pre-galvanised tube mechanical properties
|Steel Grade||Tensile Strength||Yield Strength|
|DX52D + Z/+ZF (Z2)||270/420n/mm2||140/300 n/mm2|
|S280GD+ Z/+ZF (Z28)||360n/mm2 min||280n/mm2 min|
|S350GD+ Z/+ZF (Z35)||420n/mm2 min||350n/mm2 min|
|S390GD+ Z/+ZF (Z39)||450n/mm2 min||390n/mm2 min|