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Q355B Cruciform Steel Column with Bolt-Connected Assembly for High-Rise Cross-Shaped Steel Column Projects
| MOQ: | 1 PCS/20 Tons |
| Price: | $1300-3000 |
| Standard Packaging: | Customized based on project |
| Delivery Period: | 30-60 Days |
| Payment Method: | L/C,D/A,D/P,T/T |
| Supply Capacity: | 15,000 t / month |
Q355B Cruciform Steel Column
,Bolt-Connected Cruciform Steel Column
,High-Rise Cross-Shaped Steel Column
Symmetric cross · Q355B · Plate-welded or H-section based · SRC or exposed
A cruciform column places steel where two directions need it at once. The section is symmetric, so it bends equally about both axes, and the outline stays square — which is what makes it fit inside a lift core, a wall line or a concrete encasement. The trade-off is weld distortion, and that is where the fabrication budget goes.
An H-column has one strong axis and one weak one. A box equalises them but is closed, so every internal detail has to be finished before the last plate goes on.
A cross equalises the two axes while leaving all four arms open. That means the welds are accessible from outside, the section can be inspected and painted, and concrete can be poured into the four re-entrant corners when the column is used as an SRC core.
The trade is torsional restraint. A closed box resists twisting by geometry; a cross does not. On a slender column that matters, and it is one reason a cross is usually specified for compression and bending rather than for torsion.
A rolled or welded H is used as the spine, and two flange plates are welded to the web on the opposite side. This is the economical route: one H-section, two plates, four fillet welds. It also inherits the H's straightness, which helps.
A core plate is set upright, and four flange plates are welded to it symmetrically. This is how large crosses and unequal-arm crosses are made, and how the section is matched to a drawing that is not symmetrical.
Whether the welds are fillet or full penetration depends on the load path. A cross carrying moment into a concrete core usually needs full penetration at the arm roots; a cross acting as a pure compression member can use fillets with a designed throat.
A cruciform column has four continuous longitudinal welds, all running the same way, all shrinking as they cool. Each one pulls the column toward its own side. Weld them in sequence and the column walks; weld them all at once and the heat input is unmanageable.
The controls are the same ones used on any long welded member, applied more strictly: a jig that holds the arms square, welding on opposite arms in alternation, back-step along each run, and a check between passes rather than only at the end.
Straightening is the last resort, not the method. A cross has four free edges and little torsional restraint, so flame correction moves it easily — and over-correcting cracks the weld that was just made.
- Straightness of each arm, not just of the spine. An arm can bow while the centre line measures true.
- Squareness of the cross, measured across opposite arms. If the arms are not at 90°, the column will not fit the rebar cage or the wall line.
- Weld profile at the arm root, where four welds meet within a short distance and the access is worst.
- End machining, so the column bears on its base plate across the full section rather than on one arm.
Most cruciform columns in high-rise work are not exposed steel: they are the core of a steel-reinforced concrete column. The concrete fills the four corners, the steel carries the axial load during construction, and the composite section carries it afterwards.
That changes the fabrication. Shear studs are welded to the arm faces to transfer load into the concrete. The stud layout, the tie positions and the cover thickness all come from the composite design, and they have to be on the fabrication drawing — studs cannot be added after the column is erected and surrounded by rebar.
If the column is to be exposed, the question is fire protection: an intumescent coating on a cross has a large perimeter for the steel it protects, which makes board or a concrete casing cheaper on most projects.
| Cross dimensions | Arm width, arm thickness, spine thickness, overall size |
|---|---|
| Route | From an H-section or from plates |
| Weld type at the arm root | Fillet or full penetration |
| Grade and execution standard | Q355B, EN 1090-2 or GB 50205 |
| SRC or exposed | And the stud layout if composite |
| Length | And the site splice position if over 12 m |
| Surface | Primed, galvanized, or fire protection system |
Send these details and we will return the fabrication drawing, the weight and a quotation.
Because the arms are open. Every weld can be made and inspected from outside, and concrete fills the four corners when the column is an SRC core. A box is stiffer in torsion, but it is closed and harder to build.
It is stronger about the weak axis and slightly weaker about the strong one. The total bending capacity in both directions is higher, which is the point of the shape.
Jig, alternate opposite arms, back-step, and check between passes. Straightening afterwards is limited, because over-correction cracks the weld.
Yes. An unequal cross is common where one direction carries more moment or where the column sits in a wall. It is built from plates rather than from an H-section.
Shear transfer into the concrete in an SRC column. They are welded before erection, to a layout that comes from the composite design.
Usually by the concrete encasement in an SRC column. If the steel is exposed, board is normally cheaper than intumescent, because a cross has a large perimeter for its steel area.
No. Galvanizing is corrosion protection only. Wind and seismic capacity come from the section, the connections and the design standard — the coating has nothing to do with it.
Send the cross dimensions, the route and the standard. We will return the fabrication drawing, the weight and a quotation.
