Rolled Steel for General Structure

This has been applied most widely among any of JIS; it ranges from bridge beams, vessels, vehicles to most of parts in construction. SS400 takes the majority in the consumption, for it has been applied to almost all machine and construction as supportive assembly. In addition, SS400 is of semi-killed steel without full deoxygenation, so the segregation of P. and S. would appear higher and makes the microstructure less uniform. It is essential to pay attention if there is any defection such as “lamination.”

Product Applications

Suitable for foot bolts, rivets, levers, hooks, brackets, welding structures. Used in conveyor chains, levers, linkage bars, pins, screws, nuts, seats, building structures, bridges, etc.

Q235B

Characteristics ▪ Low-carbon structural steel with a carb

MORE
Q235B

Characteristics

▪ Low-carbon structural steel with a carbon content of approximately 0.12–0.20%. It exhibits low carburizing capacity and is well-suited for general welding.
▪ Excellent ductility and toughness, allowing for easy cold bending, cold stamping, and roll/press forming.
▪ Outstanding weldability; ideal for conventional shielded metal arc welding (SMAW) and gas metal arc welding (GMAW). It is highly resistant to cold cracking and typically does not require post-weld heat treatment (PWHT).
▪ Good cold workability; readily drawn or rolled into round bars, flat bars, and square bars.
▪ Stable performance at ambient temperatures with moderate low-temperature toughness; special consideration is required for applications below -20°C.
▪ Standard corrosion resistance; surface anti-rust treatment (such as painting or galvanizing) is usually required.


Mechanical Properties

▪ Yield Strength: ≥ 235 MPa
▪ Tensile Strength: 375–450 MPa
▪ Elongation: ≥ 26% (depending on material thickness and specifications)


Applications

▪ General building and civil structural engineering.
▪ Steel rebars, sheet metal, and structural profiles (sections).
▪ Machine frames and auxiliary bridge components.
▪ Light-to-medium load components in general machinery manufacturing.


Common Components

▪ Brackets, mounts, and bases.
▪ Tie rods and connecting rods.
▪ Pins, bolts, nuts, and collars/bushings.
▪ Welded frameworks and machine enclosure supports

Close
Q235A

Characteristics ▪ Belongs to the same Q235 series as Q235

MORE
Q235A

Characteristics

▪ Belongs to the same Q235 series as Q235B, but Grade A has wider control limits for sulfur and phosphorus (typically S ≤ 0.050%), with lower impact toughness requirements than Grade B.
▪ Moderate carbon content, retaining good ductility, toughness, weldability, and cold workability.
▪ Suited for general structural applications and components where high impact toughness is not required.
▪ Excellent weldability; widely used in conventional welded structures and generally does not require preheating.
▪ Cost-effective, making it ideal for large-scale production and general-purpose applications.
▪ Unsuitable for low-temperature or high-impact environments, such as frigid climates or high-vibration areas.


Mechanical Properties

▪ Yield Strength: ≥ 235 MPa
▪ Tensile Strength: 375–500 MPa
▪ Elongation: ≥ 26% (depending on material thickness and specifications)


Applications

▪ General construction materials (such as steel plates, I-beams, and channels).
▪ Auxiliary materials in machinery manufacturing.
▪ General structural components.
▪ Secondary/auxiliary components for bridges and shipbuilding.


Common Components

▪ Tie rods and lifting hooks.
▪ Bolts and connecting rods.
▪ Mandrels (spindles) and pins.
▪ Welded assemblies, support frames, and general structural round bars.

Close
Gr.36

Characteristics ▪ Carbon structural steel for general app

MORE
Gr.36

Characteristics

▪ Carbon structural steel for general applications; a widely used ASTM grade featuring moderate strength and good weldability.
▪ Excellent plasticity and ductility, allowing for easy cold bending, flanging, and stamping.
▪ Outstanding weldability; commonly used in conventional welded structures without the need for complex preheating procedures.
▪ Good cold and hot workability, highly suitable for rolling into steel bars, structural sections, and plates.
▪ Standard corrosion resistance; surface treatment is required.
▪ Primarily used in general structural systems; not intended for high-strength or low-temperature environments.


Mechanical Properties

▪ Yield Strength: ≥ 250 MPa
▪ Tensile Strength: ~365 MPa (Note: Standard ASTM A36 ranges from 400–550 MPa)
▪ Elongation: ≥ 22% (depending on material thickness and specifications)


Applications

▪ Rolled steel materials for general structural use.
▪ Steel components and machinery frames.
▪ Non-high-load structural components.
▪ Industrial equipment enclosures.


Common Components

▪ Brackets and frameworks.
▪ Connection plates and base plates.
▪ Reinforcements (stiffeners).
▪ General structural round bars and flat bars.

Close
Gr.50

Characteristics ▪ High-strength structural steel (such as

MORE
Gr.50

Characteristics

▪ High-strength structural steel (such as the ASTM A572 Gr. 50 series), featuring a yield strength significantly higher than that of A36 / Gr. 36.
▪ Slightly higher carbon content with stricter control over alloying elements, providing superior strength and rigidity.
▪ Maintains good plasticity and toughness, though slightly lower than A36 and Q235 grades.
▪ Fair weldability; however, preheating and post-weld heat treatment (PWHT) may be required for heavy thicknesses or high-restraint joints to prevent cold cracking.
▪ Well-suited for structural designs aimed at reducing cross-sectional dimensions and minimizing structural weight.
▪ Slightly higher cost compared to standard A36 / Q235 grades.


Mechanical Properties

▪ Yield Strength: ≥ 345 MPa
▪ Tensile Strength: ≥ 450 MPa
▪ Elongation: ≥ 21% (depending on material thickness and specifications)


Applications

▪ High-strength welded structures.
▪ Primary structural components for bridges and buildings.
▪ Load-bearing members and primary stress-carrying machinery components.
▪ High-load structures.


Common Components

▪ Gusset plates and structural bearings/supports.
▪ Hangers and chassis/frame components.
▪ Structural connections.
▪ Highly stressed connecting rods and bearing housing bases.

Close
SS400

Characteristics ▪ The most common rolled steel for genera

MORE
SS400

Characteristics

▪ The most common rolled steel for general structures in the Japanese JIS standard, where "400" denotes the minimum tensile strength of 400 MPa.
▪ Low carbon content, offering good weldability and ductility, allowing for easy cold bending and flanging.
▪ High plasticity; well-suited for stamping, drawing, and rolling into steel bars, structural shapes, and plates.
▪ Outstanding weldability; commonly used in conventional welded structures without the need for complex heat treatments.
▪ Cost-effective with excellent market availability, making it a highly prevalent general structural material in Taiwan and Japan.
▪ Standard corrosion resistance; surface anti-rust treatment is required.


Mechanical Properties

▪ Minimum Tensile Strength: 400 MPa
▪ Elongation: ≥ 20% (depending on material thickness and specifications)
▪ Frequently cross-referenced with Q235 and ASTM A36 in practical engineering.


Applications

▪ Bridges, shipbuilding, and vehicles.
▪ Buildings and general machinery construction.
▪ Secondary/auxiliary materials for nearly all machinery and structural assemblies.


Common Components

▪ Brackets and structural angles (angle iron).
▪ Bases and reinforcement plates (gusset plates/stiffeners).
▪ General structural parts.
▪ Tie rods, connecting rods, and support mounts.

Close
SS490

Characteristics ▪ A general structural steel with higher

MORE
SS490

Characteristics

▪ A general structural steel with higher strength than SS400, where "490" denotes the minimum tensile strength of 490 MPa.
▪ Features elevated strength, making it ideal for applications requiring higher load-bearing capacity without resorting to alloy steels.
▪ Maintains good plasticity and toughness, though slightly lower than those of SS400.
▪ Fair weldability; however, due to its higher strength level, preheating may be required for heavy thicknesses or high-restraint joints.
▪ Excellent cold and hot workability, highly suitable for rolling into steel bars, structural shapes, and plates.
▪ Primarily utilized for structural components subjected to higher stress.


Mechanical Properties

▪ Minimum Tensile Strength: 490 MPa
▪ Elongation: Approximately 18–22% (depending on material thickness and specifications)
▪ Classified as a higher-strength structural steel under JIS standards.


Applications

▪ Structural members, as well as highly stressed steel bars and structural shapes.
▪ General engineering components.
▪ High-stress regions in bridge and vehicle structures requiring superior strength.


Common Components

▪ Chassis/frame components and support members.
▪ Mounting bases and reinforcement ribs (stiffeners).
▪ Structural brackets and frameworks.
▪ Highly stressed connecting rods and bearing housings.

Close
Q255B

Characteristics ▪ Strength sits between Q235 and higher-s

MORE
Q255B

Characteristics

▪ Strength sits between Q235 and higher-strength structural steels; frequently utilized as a medium-strength material.
▪ Slightly higher carbon content than Q235, providing elevated strength and rigidity, though with a marginal reduction in plasticity and toughness.
▪ Fair weldability; the necessity of preheating must be evaluated based on material thickness and joint restraint.
▪ Good cold workability; readily drawn or rolled into round bars and flat bars.
▪ Cost is slightly higher than Q235, but lower than high-strength alloy steels.
▪ Well-suited for applications requiring moderate strength upgrades without resorting to high-strength alloy steels.


Mechanical Properties

▪ Comparable counterparts typically align with similar ASTM A572 grades; precise matching should be verified against relevant standards and suppliers.
▪ Typically exhibits higher strength than Q235, but remains slightly lower than Q355.


Applications

▪ General structural engineering.
▪ Machinery components and parts.
▪ Applications requiring moderate strength upgrades where high-strength steel is unnecessary.


Common Components

▪ Connecting rods and brackets.
▪ Mounting bases and backing plates (shims).
▪ Stress-bearing components.
▪ General structural steel bars.

Close
Gr.40

Characteristics ▪ Medium-strength structural steel, commo

MORE
Gr.40

Characteristics

▪ Medium-strength structural steel, commonly used for transitional structural applications, with strength intermediate between A36 / Gr. 36 and Gr. 50.
▪ Good plasticity and toughness; fair weldability.
▪ The necessity of preheating during welding must be evaluated for heavy thicknesses or high-restraint joints.
▪ Excellent cold and hot workability, highly suitable for rolling into steel bars, structural shapes, and plates.
▪ Cost and strength occupy a mid-range position, making it well-suited for designs requiring an optimal balance between performance and cost.


Mechanical Properties

▪ Comparable counterparts typically align with similar ASTM A572 grades (such as Gr. 42/45); mechanical properties vary by standard.
▪ Yield and tensile strengths sit between those of Gr. 36 and Gr. 50.


Applications

▪ Machinery structural components.
▪ General load-bearing members.
▪ Welded structures.


Common Components

▪ Brackets and frameworks.
▪ Connections and mounting plates (base plates).
▪ Medium-duty connecting rods.

Close

Steel data

Standard Code Spec No. Material No. Mark
CNS 2473 SS400
JIS G3101 SS400
ASTM A36
JIS G3101 SS330
ASTM A570 Gr.30
DIN 17100 1.0036 USt37-2
(C)% (Mn)% (P)% (S)% (N)% (Cu)% Thickness(mm) Yield strength(Mpa) Tensile strength(Mpa) Elongation(%)
≦ 0.05 ≦ 0.05 ≦ 16 ≧ 245 400~510 ≧ 24
≦ 0.05 ≦ 0.05 ≦ 16 ≧ 245 400~510 ≧ 21
≦ 0.25 ≦ 0.04 ≦ 0.05 ≧ 250 400~550
≦ 0.05 ≦ 0.05 ≦ 16 ≧ 205 330~430 ≧ 26
≦ 0.25 ≦ 0.9 ≦ 0.035 ≦ 0.04 ≦ 0.2 ≧ 205 ≧ 340 ≧ 25
≦ 0.2 ≦ 0.05 ≦ 0.045 ≦ 0.008 16~40 ≧ 225 340~470 ≧ 26