What is Square hollow sections?
A square hollow section is a closed tube of square cross-section, cold-formed from hot-rolled strip and welded along one edge by high-frequency induction (ERW): the strip is slit to the developed width, roll-formed into a round, welded, then shaped square by sizing rolls, cut to 6 or 12 m and bundled. EN 10219 governs it (the hot-finished alternative, EN 10210, is rare and dearer). The closed shape is the point: for the same weight a square tube has far higher torsional and minor-axis stiffness than an angle or a channel, four flat faces to weld or bolt to, and no inside to paint. That makes it the universal fabrication section — from 15×15×1.2 furniture tube to 250×250×10 columns — and the reason the market calls it by a dozen names (box section, square pipe, MS square tube, kare profil). Our Dilovası mill rolls the range in S235JRH (ST37) as standard and S355J2H (ST52) in the structural sizes, from 1.2 to 10 mm wall; the table above is the actual production list with masses per EN 10219-2, not a catalogue copy.
Square hollow section sizes and weight per metre
Every size we roll, with wall, kg/m, kg per 6 m bar and bars per ton — from our production list; nominal mass per EN 10219-2.
| Size (mm) | Wall (mm) | kg/m | kg per 6 m bar | Bars per ton |
|---|---|---|---|---|
| 15 × 15 | 1.5 | 0.64 | 3.84 | 260 |
| 15 × 15 | 2 | 0.82 | 4.92 | 203 |
| 16 × 16 | 1.5 | 0.68 | 4.1 | 244 |
| 20 × 20 | 1.5 | 0.85 | 5.1 | 196 |
| 20 × 20 | 1.9 | 1.04 | 6.24 | 160 |
| 20 × 20 | 2 | 1.09 | 6.54 | 153 |
| 20 × 20 | 2.5 | 1.37 | 8.22 | 122 |
| 25 × 25 | 1.5 | 1.07 | 6.42 | 156 |
| 25 × 25 | 1.9 | 1.32 | 7.92 | 126 |
| 25 × 25 | 2 | 1.38 | 8.28 | 121 |
| 25 × 25 | 2.5 | 1.73 | 10.38 | 96 |
| 25 × 25 | 3 | 2.05 | 12.3 | 81 |
| 30 × 30 | 1.5 | 1.26 | 7.56 | 132 |
| 30 × 30 | 1.9 | 1.56 | 9.36 | 107 |
| 30 × 30 | 2 | 1.64 | 9.84 | 102 |
| 30 × 30 | 2.5 | 2.06 | 12.36 | 81 |
| 30 × 30 | 3 | 2.45 | 14.7 | 68 |
| 30 × 30 | 4 | 3.18 | 19.08 | 52 |
| 35 × 35 | 1.5 | 1.5 | 9 | 111 |
| 35 × 35 | 2 | 1.95 | 11.7 | 85 |
| 35 × 35 | 2.5 | 2.39 | 14.34 | 70 |
| 35 × 35 | 3 | 2.82 | 16.92 | 59 |
| 40 × 40 | 1.5 | 1.67 | 10.02 | 100 |
| 40 × 40 | 1.9 | 2.08 | 12.48 | 80 |
| 40 × 40 | 2 | 2.18 | 13.08 | 76 |
| 40 × 40 | 2.4 | 2.58 | 15.48 | 65 |
| 40 × 40 | 2.5 | 2.69 | 16.14 | 62 |
| 40 × 40 | 2.9 | 3.09 | 18.54 | 54 |
| 40 × 40 | 3 | 3.22 | 19.32 | 52 |
| 40 × 40 | 4 | 4.19 | 25.14 | 40 |
| 40 × 40 | 5 | 5.13 | 30.78 | 32 |
| 45 × 45 | 1.5 | 1.91 | 11.46 | 87 |
| 45 × 45 | 2 | 2.5 | 15 | 67 |
| 45 × 45 | 2.5 | 3.09 | 18.54 | 54 |
| 45 × 45 | 3 | 3.66 | 21.96 | 46 |
| 45 × 45 | 4 | 4.77 | 28.62 | 35 |
| 45 × 45 | 5 | 5.85 | 35.1 | 28 |
| 50 × 50 | 1.5 | 1.83 | 10.98 | 91 |
| 50 × 50 | 1.9 | 2.28 | 13.68 | 73 |
| 50 × 50 | 2 | 2.39 | 14.34 | 70 |
| 50 × 50 | 2.4 | 2.83 | 16.98 | 59 |
| 50 × 50 | 2.5 | 2.95 | 17.7 | 56 |
| 50 × 50 | 2.9 | 3.4 | 20.4 | 49 |
| 50 × 50 | 3 | 3.55 | 21.3 | 47 |
| 50 × 50 | 4 | 4.66 | 27.96 | 36 |
| 50 × 50 | 5 | 5.74 | 34.44 | 29 |
| 60 × 60 | 1.5 | 2.25 | 13.5 | 74 |
| 60 × 60 | 1.9 | 2.78 | 16.68 | 60 |
| 60 × 60 | 2 | 2.91 | 17.46 | 57 |
| 60 × 60 | 2.4 | 3.43 | 20.58 | 49 |
| 60 × 60 | 2.5 | 3.58 | 21.48 | 47 |
| 60 × 60 | 2.9 | 4.17 | 25.02 | 40 |
| 60 × 60 | 3 | 4.36 | 26.16 | 38 |
| 60 × 60 | 4 | 5.73 | 34.38 | 29 |
| 60 × 60 | 5 | 7.07 | 42.42 | 24 |
| 70 × 70 | 1.5 | 2.67 | 16.02 | 62 |
| 70 × 70 | 1.9 | 3.35 | 20.1 | 50 |
| 70 × 70 | 2 | 3.5 | 21 | 48 |
| 70 × 70 | 2.4 | 4 | 24 | 42 |
| 70 × 70 | 2.5 | 4.17 | 25.02 | 40 |
| 70 × 70 | 2.9 | 4.88 | 29.28 | 34 |
| 70 × 70 | 3 | 5.1 | 30.6 | 33 |
| 70 × 70 | 4 | 6.73 | 40.38 | 25 |
| 70 × 70 | 5 | 8.32 | 49.92 | 20 |
| 70 × 70 | 6 | 10 | 60 | 17 |
| 75 × 75 | 2 | 3.76 | 22.56 | 44 |
| 75 × 75 | 3 | 5.57 | 33.42 | 30 |
| 80 × 80 | 1.5 | 3.08 | 18.48 | 54 |
| 80 × 80 | 1.9 | 3.83 | 22.98 | 44 |
| 80 × 80 | 2 | 4.01 | 24.06 | 42 |
| 80 × 80 | 2.4 | 4.79 | 28.74 | 35 |
| 80 × 80 | 2.5 | 5 | 30 | 33 |
| 80 × 80 | 2.9 | 5.82 | 34.92 | 29 |
| 80 × 80 | 3 | 6.1 | 36.6 | 27 |
| 80 × 80 | 4 | 8.06 | 48.36 | 21 |
| 80 × 80 | 5 | 10 | 60 | 17 |
| 80 × 80 | 6 | 12.07 | 72.42 | 14 |
| 90 × 90 | 2 | 5.53 | 33.16 | 30 |
| 90 × 90 | 2.4 | 6.6 | 39.61 | 25 |
| 90 × 90 | 2.5 | 6.87 | 41.21 | 24 |
| 90 × 90 | 2.9 | 7.93 | 47.59 | 21 |
| 90 × 90 | 3 | 8.2 | 49.17 | 20 |
| 90 × 90 | 4 | 10.8 | 64.81 | 15 |
| 90 × 90 | 5 | 13.35 | 80.07 | 12 |
| 90 × 90 | 6 | 15.83 | 94.96 | 11 |
| 100 × 100 | 2 | 5.05 | 30.3 | 33 |
| 100 × 100 | 2.4 | 6.06 | 36.36 | 28 |
| 100 × 100 | 2.5 | 6.33 | 37.98 | 26 |
| 100 × 100 | 2.9 | 7.35 | 44.1 | 23 |
| 100 × 100 | 3 | 7.67 | 46.02 | 22 |
| 100 × 100 | 4 | 10.16 | 60.96 | 16 |
| 100 × 100 | 5 | 12.6 | 75.6 | 13 |
| 100 × 100 | 6 | 15.36 | 92.16 | 11 |
| 100 × 100 | 8 | 20.46 | 122.76 | 8 |
| 110 × 110 | 2.5 | 8.44 | 50.63 | 20 |
| 110 × 110 | 3 | 10.08 | 60.47 | 17 |
| 110 × 110 | 4 | 13.31 | 79.88 | 13 |
| 110 × 110 | 5 | 16.49 | 98.91 | 10 |
| 110 × 110 | 6 | 19.59 | 117.56 | 9 |
| 110 × 110 | 8 | 25.62 | 153.73 | 7 |
| 120 × 120 | 2.5 | 7.68 | 46.08 | 22 |
| 120 × 120 | 3 | 9.29 | 55.74 | 18 |
| 120 × 120 | 4 | 12.36 | 74.16 | 13 |
| 120 × 120 | 5 | 15.42 | 92.52 | 11 |
| 120 × 120 | 6 | 18.79 | 112.74 | 9 |
| 120 × 120 | 8 | 25.49 | 152.94 | 7 |
| 140 × 140 | 3 | 10.91 | 65.46 | 15 |
| 140 × 140 | 4 | 14.54 | 87.24 | 11 |
| 140 × 140 | 5 | 18.14 | 108.84 | 9 |
| 140 × 140 | 6 | 22.18 | 133.08 | 8 |
| 140 × 140 | 8 | 30.16 | 180.96 | 6 |
| 150 × 150 | 3 | 11.68 | 70.08 | 14 |
| 150 × 150 | 4 | 15.57 | 93.42 | 11 |
| 150 × 150 | 5 | 19.44 | 116.64 | 9 |
| 150 × 150 | 6 | 23.75 | 142.5 | 7 |
| 150 × 150 | 8 | 32.32 | 193.92 | 5 |
| 175 × 175 | 3 | 13.71 | 82.26 | 12 |
| 175 × 175 | 4 | 18.28 | 109.68 | 9 |
| 175 × 175 | 5 | 22.83 | 136.98 | 7 |
| 175 × 175 | 6 | 27.94 | 167.64 | 6 |
| 175 × 175 | 8 | 38.07 | 228.42 | 4 |
| 200 × 200 | 4 | 21 | 126 | 8 |
| 200 × 200 | 5 | 26.24 | 157.44 | 6 |
| 200 × 200 | 6 | 32.13 | 192.78 | 5 |
| 200 × 200 | 8 | 43.83 | 262.98 | 4 |
| 200 × 200 | 10 | 56.94 | 341.64 | 3 |
| 250 × 250 | 5 | 33.07 | 198.42 | 5 |
| 250 × 250 | 6 | 40.51 | 243.06 | 4 |
| 250 × 250 | 8 | 55.35 | 332.1 | 3 |
| 250 × 250 | 10 | 74.07 | 444.42 | 2 |
Nominal mass per EN 10219-2 with corner radii; 6 m standard length, 12 m on request.
Grades, standards and tolerances
| Grade / standard | Yield (MPa) | Note |
|---|---|---|
| S235JRH — EN 10219-1 | ≥ 235 | the standard grade for all black sections from stock |
| S275J0H | ≥ 275 | to order |
| S355J2H | ≥ 355 | thick-wall and structural sections, stock in common sizes |
| ST37 / ST52 | 235 / 355 | DIN names still used in tenders |
| ASTM A500 Gr. B / C | 290 / 345 | ASTM projects, to order |
Cold-formed to EN 10219-1/2 (tolerances: outside dimension ±1 %, wall ±10 %, straightness 0.2 %, corner radius 1.6–2.4 t). CE-marked under EN 10219-1; strip certificates EN 10204 3.1.
Lengths and stock
Standard length 6 m (+50/−0), 12 m on request for 60×60 and above; cut lengths on the mill saw to ±3 mm. Stock at Dilovası: 20×20 to 100×100 in the common walls (1.5, 2, 2.5, 3, 4 mm) in S235JRH; 100×100×5 to 150×150×6 in S355J2H; other combinations rolled within a week. Tolerances per EN 10219-2: outside dimension ±1 % (min ±0.5 mm), wall ±10 %, squareness 90° ±1°, straightness 0.2 % of length, twist 2 mm + 0.5 mm/m.
Cutting, welding and finishing
Sawing to length (straight or mitred), CNC laser tube cutting (holes, slots, notches, copes — our own 3D tube laser), drilling, bending on mandrel benders (40×40 and below), welding of frames and trusses, hot-dip galvanizing to EN ISO 1461 (vent holes drilled), blast-and-prime or powder coating. Fabricated assemblies to EN 1090-2 EXC2 on request.
Where it is used
- Columns, posts and truss members in light steel buildings
- Fence, gate, railing and balustrade frames
- Machine guards, racks, workbenches and furniture
- Trailer, truck-body and container frames
- Solar mounting structures and greenhouse frames
- Sign gantries, canopies and shade structures
SHS vs RHS vs round tube
Square (SHS) gives equal stiffness both ways and four flat faces — the default for columns, frames and anything bolted on two axes. Rectangular (RHS) puts more depth in one direction for beams and rails. Round tube is cheaper per kilogram of bending strength in torsion and is easier to bend, but harder to connect flat. All three come off the same mill; see the overview hollow sections and the coated variants galvanized square tube, cold-rolled box section and pre-painted box section.
Price
Square tube is priced per ton on our tube-mill list; the bands below separate the volume range (40–120 mm), the thin-wall small sizes (higher per ton because of strip and speed) and the heavy sizes. S355J2H adds the grade premium; cutting, galvanizing and laser work are per piece.
Bands from our weekly export list (September 2026), FOB Istanbul, full-container quantities, excluding freight and certificates. Firm price per project on RFQ within one working day.
Export and packing
Packing for Square hollow sections: bundles of one size (0.8–2 t), four steel straps, corner boards, a tag with size × wall × length, grade, heat and count; coated sections are separated with paper. 6 m bundles fill a 40' HC at 24–25 t; 12 m on flat-rack or breakbulk from Derince. Tariff 7306.61.
| Term | Detail |
|---|---|
| MOQ | 5 t (mixed sizes accepted) |
| Incoterms | FOB Istanbul · CIF / CFR Gulf, Africa · DAP EU, Balkans, Iraq, Caucasus · DAP Aktau |
| Lead time | Stock sizes 20×20–100×100: 2–5 working days; other sizes 5–10 days from the mill |
| Packing | Bundles 0.8–2 t, strapped, tagged |
| Container / truck | 40' HC ≈ 24–25 t of 6 m; 12 m flat-rack |
| Documents | Invoice, packing list, EN 10204 3.1, CE DoP (EN 10219-1), certificate of origin; SASO / SONCAP / PVoC on request |
| Payment | 30% advance, balance against B/L copy; L/C at sight above 100 t |
Certificates
Every bundle of Square hollow sections is traceable to the strip heat: EN 10204 3.1 certificate with chemistry and mechanicals, our tube-mill inspection record (dimensions, weld flattening test) and the CE declaration to EN 10219-1; 3.2 on request.
How to order
Send size × wall × length, grade, quantity in pieces or tons (mixed sizes welcome), and any cutting, drilling or coating; a cut list or drawing gets a per-line weight and price.
Standards
- EN 10219-1/2 — cold-formed welded structural hollow sections
- EN 10025-2 / EN 10219-1 grades S235JRH, S275J0H, S355J2H
- ASTM A500 on request
- EN 10204 3.1; CE marking
Grades
Grade data sheets (chemistry, mechanicals, equivalents) are on our reference site: S235JRH · S355J2H · S275J0H
Frequently asked questions
What is a square hollow section?
A cold-formed, high-frequency-welded square steel tube to EN 10219 — also called square tube, box section or MS square pipe — from 15×15 to 250×250 mm in walls of 1.2–10 mm.
What sizes of square tube do you make?
22 sizes from 15×15 to 250×250 mm in 1.2–10 mm walls; the full production list with kg/m is in the table above. 20×20 to 100×100 are stocked daily.
How much does 40×40×2 square tube weigh?
2.18 kg/m — 13.1 kg per 6 m bar, about 76 bars per ton; 50×50×3 is 4.31 kg/m and 100×100×4 is 11.7 kg/m.
What grade is square hollow section?
S235JRH to EN 10219-1 as standard (yield ≥ 235 MPa); S355J2H for structural sizes; ASTM A500 Gr. B/C to order.
What is the difference between EN 10219 and EN 10210 hollow sections?
EN 10219 sections are cold-formed and welded (ours); EN 10210 are hot-finished, with sharper corners and no cold-work residual stress, at a higher price and longer lead time.
Can square tube be galvanized?
Yes — hot-dip galvanized to EN ISO 1461 after fabrication (vent holes required) or supplied pre-galvanized from Z275 strip; see the galvanized square tube page.