{"id":6672,"date":"2026-11-02T04:33:51","date_gmt":"2026-11-02T04:33:51","guid":{"rendered":"https:\/\/www.ggsteelstruct.com\/?page_id=6672"},"modified":"2026-11-04T06:48:07","modified_gmt":"2026-11-04T06:48:07","slug":"welded-box-columns","status":"publish","type":"page","link":"https:\/\/www.ggsteelstruct.com\/zh\/products\/welded-box-columns\/","title":{"rendered":"Welded Box Columns & Beams"},"content":{"rendered":"
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Home<\/a> \/ Products<\/a> \/ Welded Box Columns & Beams<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t

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Primary Steel<\/div>\t\t\t\t<\/div>\n\t\t\t\t
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Welded box columns and beams for frames where the node sets the geometry<\/h1>\t\t\t\t<\/div>\n\t\t\t\t
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Four-plate box sections with internal diaphragms, full-penetration welds where the design needs them, and a UT record per seam. Built for high-rise SRC frames, transfer levels and heavy industrial columns.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t

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\n\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\tCapability table<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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18,472 t<\/h3>\t\t\t\t<\/div>\n\t\t\t\t
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SRC box and H members, CGN HQ<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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Q420GJC<\/h3>\t\t\t\t<\/div>\n\t\t\t\t
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Thick-plate grade, Zengcheng tower<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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100 mm<\/h3>\t\t\t\t<\/div>\n\t\t\t\t
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Maximum plate thickness<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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100%<\/h3>\t\t\t\t<\/div>\n\t\t\t\t
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UT on CJP seams as standard<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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\n\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\tBox vs H<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\tCapabilities<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\tWelding & NDT<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\tTolerances<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\tSRC interfaces<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\tCost drivers<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\tProject<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\tFAQ<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\tGet a Quote<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Selection<\/div>\t\t\t\t<\/div>\n\t\t\t\t
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Box or H section: when each one wins<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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A box column costs more per ton to make. It earns that back where bending comes from two directions, where torsion matters, or where concrete fills or wraps the section.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Condition<\/th>Box<\/th>H<\/th><\/tr><\/thead>
Biaxial bending, corner columns<\/th>Better<\/strong><\/td>Weak axis governs<\/td><\/tr>
Torsion or transfer loads<\/th>Better<\/strong><\/td>Poor<\/td><\/tr>
Concrete-filled (CFT) or SRC<\/th>Both<\/strong><\/td>SRC only<\/td><\/tr>
Exposed architectural column<\/th>Clean faces<\/strong><\/td>Visible flanges<\/td><\/tr>
Simple axial load, one bending axis<\/th>Over-designed<\/td>Cheaper<\/strong><\/td><\/tr>
Fabrication hours per ton<\/th>Higher<\/td>Lower<\/strong><\/td><\/tr>
Beam connections<\/th>Through-diaphragm or stiffened<\/td>Simple end plates<\/strong><\/td><\/tr><\/tbody><\/table>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\tH vs I vs box: the full comparison \u2192<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Capabilities<\/div>\t\t\t\t<\/div>\n\t\t\t\t
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What we fabricate<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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Limits are for a single shipping piece. Longer or heavier members are split with site splices designed for erection.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Parameter<\/th>Range<\/th>Notes<\/th><\/tr><\/thead>
Section size<\/th>300 \u00d7 300 to 1,500 \u00d7 1,500 mm<\/td>Rectangular and tapered sections<\/td><\/tr>
Plate thickness<\/th>8\u2013100 mm<\/td>Through-thickness grade Z15\/Z25\/Z35 for thick plate loaded through its thickness (GB\/T 5313, EN 10164)<\/td><\/tr>
Piece length<\/th>Up to 18 m<\/td>11.8 m fits a 40HQ; longer on flat rack or break-bulk<\/td><\/tr>
Piece weight<\/th>Up to 40 t<\/td>Set by workshop cranes and site crane capacity<\/td><\/tr>
Steel grades<\/th>Q235B, Q355B\/C\/D, Q390, Q420GJC, Q460; ASTM A572 Gr50, A992; EN S355JR\/J2<\/td>Mill certificates to EN 10204 3.1<\/td><\/tr>
Internal diaphragms<\/th>Fillet-welded inside, or electroslag (ESW) through the skin plate<\/td>ESW where the box is too small to weld inside<\/td><\/tr>
Attachments<\/th>Shear studs, rebar holes and couplers, beam stubs, corbels<\/td>Positioned from the combined steel and rebar model<\/td><\/tr>
End preparation<\/th>Milled ends for contact-bearing splices<\/td>Contact checked per piece<\/td><\/tr><\/tbody><\/table>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Welding and NDT<\/div>\t\t\t\t<\/div>\n\t\t\t\t
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How a box column is built, and where it is checked<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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The order of welding decides the final straightness more than any correction afterwards. Each step is a hold point in the ITP.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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01<\/div>\t\t\t\t<\/div>\n\t\t\t\t
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Plate cutting<\/h4>\t\t\t\t<\/div>\n\t\t\t\t
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CNC flame or plasma cut, bevels for CJP welds. Heat numbers transferred to each piece. Thick plate UT-scanned for laminations (GB\/T 2970, EN 10160).<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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02<\/div>\t\t\t\t<\/div>\n\t\t\t\t
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U-section fit-up<\/h4>\t\t\t\t<\/div>\n\t\t\t\t
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Three plates on a jig, diaphragms positioned and checked against the model.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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03<\/div>\t\t\t\t<\/div>\n\t\t\t\t
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Diaphragm welding<\/h4>\t\t\t\t<\/div>\n\t\t\t\t
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Fillet welds inside, or ESW through the closing plate where access is too tight.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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04<\/div>\t\t\t\t<\/div>\n\t\t\t\t
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Closing and corner welds<\/h4>\t\t\t\t<\/div>\n\t\t\t\t
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Fourth plate closed, corners welded by SAW in a balanced sequence to control twist. Preheat by thickness and carbon equivalent.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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05<\/div>\t\t\t\t<\/div>\n\t\t\t\t
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UT and MT<\/h4>\t\t\t\t<\/div>\n\t\t\t\t
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CJP seams ultrasonically tested, fillets MT tested, to the acceptance class in your specification.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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06<\/div>\t\t\t\t<\/div>\n\t\t\t\t
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Straightening and milling<\/h4>\t\t\t\t<\/div>\n\t\t\t\t
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Heat or press correction, end milling, dimensional report per piece.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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\n\t\t\t\t\t\t\t\t\tWPS and PQR.<\/b> Qualified procedures for each joint type, plate range and position, issued with the ITP.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\tAcceptance criteria.<\/b> GB 50661, AWS D1.1 or ISO 5817 level B\/C, whichever your specification names.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\tThird-party NDT.<\/b> Your inspector can witness or repeat UT on any seam before coating. See weld testing<\/a>.\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Tolerances<\/div>\t\t\t\t<\/div>\n\t\t\t\t
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Box section limits under EN 1090-2<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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Twist is the usual failure. A box that is straight but twisted will not line up with beam stubs on site. Balanced corner welding and diaphragm placement prevent it. Values below are the functional tolerances of EN 1090-2 Annex B.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Item<\/th>Class 1<\/th>Class 2<\/th><\/tr><\/thead>
Section width or depth b < 900 mm<\/th>\u00b13 mm<\/td>\u00b12 mm<\/td><\/tr>
Section width or depth 900 \u2264 b < 1,800 mm<\/th>\u00b1b\/300<\/td>\u00b1b\/450<\/td><\/tr>
Section width or depth b \u2265 1,800 mm<\/th>\u00b16 mm<\/td>\u00b14 mm<\/td><\/tr>
Twist over length L<\/th>L\/700, not less than 4 mm and not more than 10 mm<\/td>L\/1000, not less than 3 mm and not more than 8 mm<\/td><\/tr>
Length, general<\/th>\u00b1(L\/5000 + 2) mm<\/td>\u00b1(L\/10000 + 2) mm<\/td><\/tr>
Length, ends for full contact bearing<\/th>\u00b11 mm<\/td>\u00b11 mm<\/td><\/tr>
Straightness<\/th>L\/1000<\/td>L\/1000<\/td><\/tr>
Gap at a contact-bearing surface<\/th>0.5 mm<\/td>0.25 mm<\/td><\/tr><\/tbody><\/table>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
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Source: EN 1090-2 Annex B (Tables B.4 and B.6, checked against the 2017 final draft). Projects to Chinese codes use GB 50205-2020. Your specification names the class and edition; class 2 is priced as such.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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SRC and concrete-filled columns<\/div>\t\t\t\t<\/div>\n\t\t\t\t
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Steel and concrete in the same column<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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Most SRC problems are clashes, not strength. Rebar, studs and diaphragms compete for the same space, and the clash is cheapest to fix in the model.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t

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