Square Hollow Section Carbon steel square tube 150x150x8mm Q235B Scaffolding Building Frame Tube

At 150 x 150 x 8 mm this is the largest square hollow section we run on the standard ERW line, and it is bought almost entirely for load bearing work: scaffolding towers, building frames, temporary works, plant support structures and heavy racking. Weight is 35.67 kg per metre, so a 6 m length is 214 kg and handling has to be planned before the truck arrives.

Q235B is the Chinese structural grade with 235 MPa minimum yield, widely accepted across Asia, Africa and the Middle East, and it is the grade most scaffolding and temporary works systems in those markets are designed around. Because the section is heavy, wall uniformity matters more than on thin wall tube: an 8 mm wall at plus 10 percent is 8.8 mm, which adds 10 percent to the weight of every length and to the freight bill.

• 235 MPa Yield Structural Grade: Q235B with certified chemistry and mechanicals, the grade specified for most scaffolding and temporary works systems in Asia and Africa.
• 8 mm Wall for Heavy Connections: Allows M20 bolted connections, welded gusset plates and socketed couplers without local reinforcement.
• High Bending Capacity: 150 mm face depth with an 8 mm wall gives the stiffness needed for tower legs and frame columns under eccentric load.
• Wall Uniformity Control: Wall measured at four points per length and held inside plus or minus 10 percent, because overweight sections cost freight on every shipment.
• Square, Straight and True: Outside dimension held to plus or minus 0.6 mm and straightness to 1.5 mm per metre, so bolted frames close without forcing.
• Cut and Drilled to Drawing: End plates, bolt holes and 45 degree mitres can be prepared before shipment to cut site labour.

Scaffolding towers and system frames, building and warehouse frames, temporary support structures, plant and equipment skids, heavy racking uprights, bridge falsework and stage and event structures. It is also used as a foundation pile casing in light duty work and as a guard post section in industrial yards. On any application where the frame is assembled and dismantled repeatedly, the corner radius and hole positions matter more than the weight, because a frame that does not close on the first attempt costs more than the steel.

This section is heavy and long, so packing is planned around handling rather than volume: bundles up to 2.5 tons, timber dunnage between layers, four steel straps, waterproof paper and PVC sleeve, and lifting points marked on the bundle tag. For 12 m lengths we confirm container type before order, since a 20 ft container cannot take them. Certificates to EN 10204 3.1 are issued per heat, and SGS or BV inspection can be arranged.

A freight note that often surprises buyers: at 35.67 kg per metre, overweight rather than volume is what fills the container. A 20 ft container will take roughly 25 tons, which is about 700 metres of this section, not the 900 metres that a volumetric calculation suggests. Ask us for a loading plan against your cut list rather than estimating from tube count.