Flat Steel Bar for Structural Supports and General Fabrication
Specification
| Parameter | Range / Options |
| Width | 10 mm： 400 mm (1/2"： 6" in imperial) |
| Thickness | 3 mm： 60 mm (1/8"： 5/8" in imperial) |
| Length | 3 m： 12 m (standard: 6m, 20ft) |
| Popular Sizes | 30×3, 30×5, 40×5, 50×5, 50×8, 50×10, 60×5, 60×8, 60×10, 80×8, 80×10, 100×10, 100×12, 120×10, 150×10 mm |
Material Standards
| Material Type | Standard | Common Grades |
| Carbon Steel | ASTM A36 | A36 (structural applications, 36 ksi yield) -5-6-7 |
| EN 10025-2 | S235JR (1.0038, formerly St37-2, equivalent to A36) -6 | |
| S355J2 (1.0577, formerly St52-3, equivalent to A572 Grade 50) -6-10 | ||
| JIS G3101 | SS400, SS490 -7 | |
| GB/T 1591 | Q235, Q345 -7 | |
| Stainless Steel | ASTM A276 | 304/L, 316/L -3-10 |
| EN 10088 | 1.4301, 1.4404 -10 | |
| Spring Steel | ASTM A29 | 5160 -7 |
| Aluminum | EN Standards | EN AW-5083, EN AW-7075 |
Manufacturing Methods
Hot Rolling:
Steel is heated above recrystallization temperature and passed through rolling mills to achieve the desired rectangular cross-section. This is the most common production method for standard flat bars, resulting in a mill-scale surface finish (scale thickness approximately 20–50 μm) . Hot rolled flat bars are suitable for general construction and fabrication where surface finish is not critical.
Cold Rolling / Drawing:
Hot-rolled bars are further processed at room temperature to achieve tighter dimensional tolerances, superior surface finish, and increased strength. Precision flat steel with regular or oversize dimensions is available for applications requiring high dimensional accuracy .
Edge Finishing Options:
Precision machined edges are deburred and smooth, offering fabrication benefits in terms of component alignment for welding and improved handling . Thermal cut edges are produced by cutting plate into narrower strips for thicker sections
Surface Finishes
Black / Natural Finish
As-rolled with mill scale, typically used for construction and general fabrication.
Shot Blasted / Pickled
Clean surface free from mill scale, prepared for painting or further treatment.
Primed / Painted
Shop-applied primer coating for temporary protection.
Hot-Dip Galvanized
Zinc coating applied per ASTM A123 or EN ISO 1461 for corrosion protection. The flat geometry is particularly well suited to galvanizing, providing consistent coverage without hidden surfaces.
Oiled
Temporary rust protection during transit.
Applications
Steel Construction and Fabrication
Flat bars are essential components in structural steelwork for frames, gusset plates, connection brackets, stiffener ribs, and base plates. S355J2 flat bars are widely used for column base plates and beam splice connections where high bearing resistance is required.
Gates, Railings and Fencing
Flat bars provide clean lines, smooth surface and mechanical strength required for balustrades, handrails, fence panels, staircases, and ornamental ironwork. They are also used in railing manufacturing and decorative products.
Machine Building and Manufacturing
Guide rails, keys, spacer plates, backing strips for welded joints, wear strips, and machine bed levelling shims. The flat cross-section allows precise machining to tight tolerances.
Transport and Agriculture
Trailer chassis reinforcement, body-building brackets, equipment mounting plates, agricultural machinery components, and transportation components .
Infrastructure and Heavy Construction
Used in bridge construction, crane sectors, and as main carrier products in building structures . Wide flat bars serve as large stiffener plates, wear liners, and heavy base plates .
Miscellaneous Fabrication
Reinforcement strips in concrete formwork, knife bars, clamping bars, hinge straps, furniture making, shipbuilding, railway spare parts, iron towers, boilers, and general workshop stock .