Hot Rolled Mild Steel JIS G3131 SPHC

What is JIS G3131 SPHC Steels?

JIS G3131 SPHC steels refer to the hot rolled mild steel grades covered under the Japanese Industrial Standard G3131. SPHC stands for “Steel Plate for Highway Bridges and Common Structures”. These are plain carbon steels commonly used for general structural applications in Japan.

Why Purchasing sample of this type of steel is significant for making your product?

Purchasing sample of JIS G3131 SPHC steel allows manufacturers to test and verify if the material meets requirements for their intended use.Properties like chemical composition, mechanical strengths can be validated on samples before bulk ordering. This reduces risks of non-conformance during actual production.Samples also enable experimental testing of weldability, machinability or other processing characteristics.

What is Hot Rolled Mild Steel?

Hot rolled mild steel is a constructional steel that undergoes controlled rolling at high temperatures above its recrystallization temperature to obtain a specific shape and size. The process enhances its mechanical properties compared to cold rolled or forged materials.

Hot Rolled Mild Steel JIS G3131 SPHC
Hot Rolled Mild Steel JIS G3131 SPHC

Why is JIS G3131 SPHC material called hot rolled Steel?

JIS G3131 SPHC grades are called hot rolled steel because that is the manufacturing process used to produce the desired profiles and sections from the semi-finished steel billets. Heating above the recrystallizing temperature allows rolling through successive calibrated rolls to achieve the final dimensional accuracy before air cooling.

Available Forms in Shangang Steel

JIS G3131 SPHC steel is commonly available as wide flats, angles, channels, beams, pipe etc in various cross-sections as required. Standard sizes range from 5mm to 250mm thickness and up to 3000mm width. Custom shapes can also be produced on special orders.

Characteristics of JIS G3131 SPHC Steels

These are plain carbon steels offering strengths between 235-415MPa.Due to the hot rolling process, they have higher strength and ductility than cast or forged grades.Surface finish ranges from mill scale to ground levels depending on end use and specifications.

The Chemical Composition of JIS G3131 SPHC Steels

The chemical composition is defined in JIS G3131 and typically contains 0.15-0.25% carbon, 0.6-1.0% manganese with small amounts of phosphorus and sulfur. This provides good machinability along with adequate mechanical properties.

Mechanical Properties of JIS G3131 SPHC Steels

Yield Strength ranges from 180-370MPa. Tensile Strength ranges from 235-440MPa based on specific grade and thickness.Elongation exceeds 20% indicating ductility.Impact toughness and fatigue strength are moderate to high as per hot rolled mild steels.

Equivalent Material Grades in Other International Standards

Equivalent grades in other standards include A36, S235JR, ST37-2 in European, British and Chinese specifications having similar mechanical properties ranges as per JIS G3131.


Common applications include general structural sections, buildings, bridges, machinery components, Pressure vessels where good formability and weldability are required at moderate to high strengths.The hot rolled process enhances viability for various fabrication techniques.