Q235 / S235JR Cold Drawn Flat Steel Bar – Sizes and Tolerances

We draw flat steel bar in Q235 / S235JR for structural and general engineering use. Drawing pulls hot rolled flat bar through a flat die, which tightens the width and thickness tolerance, straightens the bar and gives a clean bright surface. Widths run from 20 mm to 200 mm, thickness from 3 mm to 40 mm.

How We Draw Flat Bar

Hot rolled flat bar is pickled to remove scale, then pulled through a flat die on our drawing line. The die tightens the width and thickness, straightens the bar and leaves a bright surface. After drawing we cut to length and deburr the edges, so the bars stack and handle cleanly in your workshop.

Sizes and Section Combinations

Flat bar is ordered by width × thickness. Our common range covers 20×5 up to 100×20 mm; larger combinations up to 200×40 mm are drawn to order. If you need an imperial section – 1"×1/4", 1"×3/8", 1-1/2"×3/8", 2"×1/2" – send the inch dimensions and we match the metric equivalent before quoting.

Tolerance and Straightness

We draw to h11 per EN 10278. For a 50×10 mm bar, h11 holds the width to ±0.16 mm and thickness to ±0.09 mm. The bar is straightened to ≤ 0.5 mm/m and checked on the line. Edges are square and deburred after cutting, which matters when bars are welded edge-to-edge or fed into a slitter.

Surface Options

Bright drawn (WD) is standard: clean, scale-free and ready to machine or weld. Peeled (WP) removes the decarburized layer for a cleaner, more uniform surface, specified when the bar goes into a finished visible part or is induction hardened. Bars can be oiled for rust protection on longer shipments.

What Customers Make From Q235 / S235JR Flat Bar

Q235 / S235JR flat bar goes into machine frames, brackets, spacers, guide strips, gussets and structural steelwork. Buyers order it when they need a flat section with straight edges and a consistent thickness to feed directly into machining or welding. The drawn finish also saves a surface preparation step compared to hot rolled bar.

Quality and Inspection

We check width, thickness, straightness and edge condition on the drawing line. Every order carries an EN 10204 3.1 mill test certificate with chemical composition and mechanical properties on request. Third-party inspection can be arranged.

Cutting, Packing and Lead Time

Standard lengths are 2,000 to 6,000 mm; we cut to your length with ±2 mm on cut pieces. Bundles are tied with steel strapping and protected for container loading. Stock sizes ship within 3–7 days; larger or non-standard sections take 15–25 days depending on quantity.

Send width, thickness, grade and length for a quote. We also draw cold drawn flat steel in higher grades and round bar on the same lines.

Welding Q235 and S235JR Flat Bar

Q235 and S235JR are both weldable without preheat at normal thicknesses. The drawn surface welds cleanly – there is no scale to burn through, which means less spatter and a smoother weld seam. For fillet welds on flat bar edges, keep the edge clean and dry; the square deburred edges give the weld a consistent root. If the welded assembly is load-bearing, specify the grade and the weld procedure at ordering so the mill certificate and your fabrication record match.

Flat Bar in Structural and Machine Frames

Flat bar is the workhorse section for frames, brackets, gussets and spacers. In a machine frame, drawn flat bar gives straight, parallel edges that align in a jig and weld square. In structural work, the consistent thickness means the section modulus is predictable and the surface needs no preparation before painting or galvanizing. Buyers order it when the part is a flat strip with controlled thickness – exactly what hot rolled bar does not always deliver.

Width, Thickness and Section Choice

Flat bar is ordered as width × thickness, and the ratio between them drives the application. Thin sections (3–8 mm thick) bend and form easily for brackets and guards. Mid sections (8–15 mm) suit frames and spacers. Thick sections (15–40 mm) are used where the bar is itself the load path – supports, tie bars, structural connections. If your drawing gives only a weight per metre or a cross-section, send the sketch and we recommend the standard combination closest to it.

Cutting and Processing Options

We supply flat bar cut to length with ±2 mm tolerance, and we can deburr, chamfer or drill holes to your layout on request. Bars are straightened after drawing, so long pieces stay true in the frame without extra straightening work. For repeated lengths, tell us the number of pieces and the length; we cut the full lot in one run so all blanks match.

Stock Program and Delivery

Common sections – 20×5, 30×8, 40×10, 50×10, 60×12, 80×15, 100×20 – ship from stock within 3–7 days. Larger combinations up to 200×40 mm are drawn to order in 15–25 days. Bundles are tied with steel strapping and protected for container loading; cut pieces can be crated for small orders.

Common Questions About Q235 / S235JR Flat Bar

Can Q235 / S235JR flat bar be welded? Yes. Both grades weld without preheat at normal thicknesses. The drawn surface is free of scale, which reduces spatter and gives a cleaner weld seam. For load-bearing welded assemblies, specify the grade and weld procedure so the mill certificate matches your fabrication record.

Do you provide mill certificates? Yes. Every order can carry an EN 10204 3.1 certificate with chemical composition and mechanical properties, and third-party inspection is arranged on request.

What is the largest flat bar you draw? Standard range is 20×3 to 200×40 mm. Longer lengths up to 12 m and non-standard combinations are quoted per order.

Can you cut and drill flat bar? We cut to length with ±2 mm tolerance, deburr the ends, and can drill hole patterns to your layout. Processing is quoted together with the material.

What is the minimum order quantity? 500 kg per size. A mixed order across several sizes is combined toward the MOQ, so a small first order to test our quality is practical.

Is galvanized flat bar available? We supply drawn bar as standard. Galvanizing can be arranged through our processing partners for structural orders; tell us the coating specification and we quote the complete supply.

Where Q235 / S235JR Flat Bar Is Specified

Structural brackets, gussets and tie bars. Flat bar is the default section for brackets, gussets and diagonal ties in frames and racks. Common sections are 50×8, 60×10 and 80×15 mm, supplied cut to length and drilled to the layout. The drawn edges are straight and square, which keeps the weld joints aligned and the bracket true when it is fitted.

Machine guards and frames. Thin sections – 20×5, 30×8, 40×10 – bend and weld cleanly for guards, screens and light frames. The scale-free surface saves a cleaning pass before painting or powder coating, and the consistent thickness keeps the bent parts parallel.

Earthing and grounding flats. 25×3 and 25×4 flat bar is a standard earthing conductor section. The drawn surface takes a clean connection to clamps and lugs, and the straightness makes long runs along cable trays and pillars neat and secure.

Conveyor and rack components. Flat bar runs as conveyor side rails, rack shelf supports and spacer strips. Order lengths are cut to the beam or shelf width with ±2 mm tolerance, so the assembly fits without trimming on site.

Inspection and Certificates

Width, thickness, straightness and surface are checked on the drawing line before cutting. EN 10204 3.1 mill certificates with chemical composition and mechanical properties are issued per order, and third-party inspection is arranged on request. For galvanized deliveries the coating weight and adhesion are confirmed against your specification.