Carbon Steel · Flat Bar

Flachstange aus Q235B-Kohlenstoffstahl

Structural-grade mild steel flat bar with balanced strength, excellent weldability and superior formability — the all-round profile for fabrication, Rahmen, supports and machinery parts.

Standard: GB/T 700 Beenden: Warmgewalzt Custom Size Available

Streckgrenze

≥235 MPa

Zugfestigkeit

370–500 MPa

Width Range

20–200 mm

01 · Produktübersicht

A versatile low-carbon structural profile

Q235B flat bar is a hot-rolled low-carbon steel section with a rectangular cross-section, produziert zu GB/T 700. Its controlled carbon content keeps the grade highly weldable while the manganese content provides dependable yield and tensile strength for everyday structural duty.

Widely used in steel structures, machine frames, Klammern, Gestelle, railings and enclosure fabrication, Q235B flat bar offers the best cost-performance balance among ordinary structural steels — easy to cut, bohren, bend and weld, available in a wide range of widths and thicknesses, and fully customizable in length.

02 · Hauptmerkmale

Why choose Q235B flat bar

Guaranteed Yield Strength

Minimum yield of 235 MPa with tensile range 370–500 MPa, verified against GB/T 700 for reliable load-bearing performance.

Excellent Weldability

Low carbon content (max 0.20%) gives a low carbon equivalent, allowing smooth MIG, TIG and arc welding without preheating for most sections.

Superior Formability

Hot-rolled microstructure bends, punches and presses cleanly, ideal for brackets, Kanäle, guards and cold-formed components.

Individueller Zuschnitt & Größen

Available in 20–200 mm width, 3–25 mm thickness and any cut length from 1 m to 12 m — cut to your exact drawing.

Consistent Tolerance

Rolled to GB/T 702 dimensional tolerances with straight edges and square corners for accurate fit-up in assemblies.

Export-Grade Packaging

Steel-strapped bundles with woven fabric or waterproof wrap, palletized for sea, rail and road transport without damage.

03 · Chemische Zusammensetzung

Chemische Zusammensetzung (Gew.-%) — GB/T 700 Q235B

Element	Kohlenstoff (C)	Silizium (Und)	Mangan (Mn)	Schwefel (S)	Phosphor (P)
Inhalt	≤ 0.20	≤ 0.35	≤ 1.40	≤ 0.045	≤ 0.045

Notiz: single values are maximum limits per GB/T 700. Residual copper ≤ 0.30%. Die Wärmeanalyse gilt für Pfannenproben.

04 · Mechanische Eigenschaften

Mechanische Eigenschaften (thickness ≤ 16 mm)

Eigentum	Streckgrenze ReH	Zugfestigkeit Rm	Dehnung A	Auswirkungen (20°C)	Härte (ca.)
Wert	≥ 235 MPa	370 – 500 MPa	≥ 26%	≥ 27 J	~ 121 HBW

Tensile strength — common structural grades comparison (MPa)

Q235B (dieses Produkt)370 – 500

A36 (ASTM)400 – 550

S235JR (IN 10025)360 – 510

SS400 (ER G3101)400 – 510

05 · Physikalische Eigenschaften

Physikalische Eigenschaften

Dichte7.85 g/cm³

Schmelzpunkt≈ 1,510 °C

Elastizitätsmodul200 GPa

Poissonzahl0.30

Wärmeleitfähigkeit (100°C)~ 50 W/(m·K)

Elektrischer Widerstand (20°C)~ 0.17 µΩ·m

Längenausdehnungskoeffizient~ 12×10⁻⁶ /°C

OberflächenbeschaffenheitMühle / black oxide

06 · Allgemeine Spezifikationen

Gängige Größen & Spezifikationen

Breite (mm)	Dicke (mm)	Länge	Toleranz	Rand
20, 25, 30, 40	3, 4, 5, 6	6 m Standard	GB/T 702	Fully rounded / Quadrat
50, 60, 80, 100	6, 8, 10, 12	6 M / Brauch	±0.5 mm (Dicke)	Straight, burr-free
120, 150, 200	12, 16, 20, 25	Up to 12 M	GB/T 702	Straight, deburred

Sizes beyond this table, customized lengths and non-standard dimensions are available on request.

07 · Anwendungen

Where Q235B flat bar is used

Steel structures, frames and light trusses
Machine frames, bases and fabricated parts
Gestelle, shelves, supports and brackets
Bridges, Geländer, guards and handrails
Electrical cabinets and distribution enclosures
Agricultural machinery and transport equipment

08 · Verarbeitung & Verpackung

Verarbeitungsdienstleistungen & Exportverpackung

Verarbeitung

Auf Länge schneiden
Bohren & punching holes
Biegen & Bildung
Shot blasting & derusting
Painting (Grundierung / epoxy)
Feuerverzinkung

Verpackung

Stahlbandbündel, 2–3 t per bundle
Woven fabric or water-proof wrap
Holzpalette / crate for sea freight
Labels with grade, Größe & batch no.
Mühlenprüfzertifikat (MTC) geliefert
3Inspektion durch Dritte akzeptabel

Need Q235B flat bar in custom sizes?

Send us your width, thickness and length requirements — we reply within 24 Stunden mit einem wettbewerbsfähigen Angebot, stock availability and shipping options.

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