JIS SUS304 304 0.5mm Stainless Steel Sheets Hot Rolled Stainless Steel Sheet For Construction

SUS304: The Global Standard for Stainless Steel

SUS304 is the Japanese Industrial Standard designation for the austenitic stainless steel that is known worldwide as 304, 1.4301, or UNS S30400. It is, by every measure, the most commercially significant stainless steel grade in existence. More 304 is produced, stocked, fabricated, and installed than all other stainless steel grades combined. This dominance is not the result of historical accident or marketing preference. It is the result of a set of properties that, taken together, address the requirements of the broadest possible range of applications.

The metallurgical foundation of SUS304 is the combination of 18.0–20.0% chromium and 8.0–10.5% nickel. Chromium is the element that makes stainless steel stainless. At concentrations above approximately 12%, chromium forms a continuous, adherent, self-healing passive oxide layer on the steel surface. This layer—only a few atoms thick—separates the reactive metal beneath from the environment, preventing the oxidation reaction that produces rust on ordinary steel. The chromium content of SUS304 at 18–20% ensures that this passive layer is robust, rapidly self-repairing, and stable across the range of atmospheric and mildly chemical environments for which the grade is specified.

Nickel serves a different but equally essential function. Nickel is an austenite stabilizer, meaning it expands the temperature range over which the face-centered cubic austenitic crystal structure is stable. At the 8.0–10.5% nickel level in SUS304, the austenitic structure is maintained at room temperature and below, providing the ductility, toughness, formability, and weldability that distinguish austenitic stainless steels from their ferritic and martensitic counterparts. The nickel also contributes to corrosion resistance, particularly in reducing acid environments, and enhances the material's resistance to stress corrosion cracking relative to lower-nickel grades.

The practical implications of this metallurgy for the construction and chemical industry user are comprehensive. SUS304 sheet and plate can be bent, formed, deep drawn, punched, sheared, and otherwise fabricated using standard sheet metal and plate processing equipment. It can be welded by all common arc welding processes—GTAW (TIG), GMAW (MIG), SMAW, and SAW—with readily available filler metals. The welded joints, properly executed, possess corrosion resistance approaching that of the parent material. The annealed material exhibits elongation of 40% minimum, enabling the severe forming operations required for architectural feature elements, tank heads, and complex fabricated assemblies.

Corrosion resistance in atmospheric exposure—the primary environment for construction applications—is excellent. SUS304 resists the full range of rural, urban, suburban, and light industrial atmospheres without rusting or surface degradation. In indoor architectural applications, the material maintains its original surface finish indefinitely with no maintenance beyond routine cleaning. In exterior applications, periodic rain washing is typically sufficient to maintain the surface appearance. For coastal or heavy industrial atmospheres containing elevated chloride or sulfur compound levels, the corrosion resistance of SUS304 should be evaluated against the specific exposure conditions, with an upgrade to molybdenum-bearing SUS316L available for environments exceeding 304's capability.

Hot Rolled Manufacturing for Construction and Industrial Supply

The hot rolling process that produces this SUS304 sheet and plate is the foundational manufacturing route for stainless steel flat products above approximately 3mm thickness, and it is also used to produce coil feedstock that is subsequently cold rolled to thinner gauges. Understanding the hot rolling process provides insight into the material properties that the fabricator and end user depend upon.

Hot rolling begins with a continuously cast slab of SUS304 stainless steel, typically 150–250mm thick. The slab is reheated to approximately 1200–1280°C, a temperature at which the steel is fully austenitic and sufficiently soft to undergo the massive thickness reductions required to reach the finished plate or sheet gauge. The reheated slab passes through a roughing mill that reduces it to an intermediate thickness, then through a finishing mill—a series of closely spaced rolling stands—that progressively reduces the material to the final ordered thickness.

The metallurgical significance of hot rolling lies in its effect on the grain structure. The cast slab possesses a coarse, dendritic grain structure resulting from the relatively slow solidification of the continuous casting process. The repeated heavy reductions of hot rolling break down this cast structure, fragmenting the dendrites and closing any centerline porosity or shrinkage cavities. The high temperature of the process allows continuous recrystallization—new, strain-free grains nucleate and grow as the metal is deformed, replacing the deformed grains with a refined, equiaxed microstructure. The total reduction from slab to plate, expressed as the ratio of starting to finishing thickness, determines the degree of grain refinement and the uniformity of the final microstructure.

After rolling to the finished gauge, the plate or coil is solution annealed. For SUS304, solution annealing is performed at 1010–1150°C, a temperature range that dissolves any chromium carbides that may have formed during cooling from the rolling temperature, recrystallizes the hot-worked grain structure into a uniform equiaxed austenitic condition, and homogenizes the distribution of chromium and nickel within the austenite matrix. Rapid cooling—typically water quenching for plate and accelerated air cooling for thin sheet—follows immediately, preventing chromium carbide precipitation during passage through the sensitization temperature range.

The final manufacturing step is descaling. The oxide scale that forms on the surface during hot rolling and annealing, while protective during high-temperature exposure, is unsuitable for fabrication or service. Descaling is accomplished by shot blasting to mechanically fracture the scale, followed by acid pickling—typically in a mixed nitric-hydrofluoric acid bath—to dissolve the residual scale and the chromium-depleted layer immediately beneath it. The resulting surface, designated No.1 finish under JIS G4304, is clean, uniformly matte, and fully corrosion-resistant. This is the standard surface condition for hot rolled plate intended for construction, tank fabrication, and structural applications.

Thickness Range: From 0.5mm Sheet to 500mm Plate

The thickness range of 0.5mm to 500mm makes this product among the most versatile flat stainless steel offerings available, spanning the full spectrum from lightweight architectural sheet to ultra-heavy industrial plate.

At 0.5mm, this material is classified as sheet—thin enough to be formed on press brakes, sheared on guillotine shears, and roll-formed into architectural profiles. In construction, 0.5mm SUS304 sheet serves as roofing material, wall cladding, fascia panels, soffit liners, and decorative interior wall panels. The sheet is typically supplied in coil form for continuous processing or cut to length for direct fabrication. At this gauge, the material is often specified with a surface finish beyond the standard No.1 hot rolled finish—2B, No.4 brushed, hairline, or mirror polish—depending on the architectural visual requirement. The hot rolled and annealed starting condition provides the formability and surface quality necessary for these finishing operations.

In the 1.0mm to 6.0mm range, the material serves the core of architectural and light industrial fabrication. Elevator cabin panels, column covers, entrance doors, handrail infill panels, equipment enclosures, and structural connection plates are produced from sheet and light plate in these thicknesses. The material combines self-supporting rigidity for moderate panel sizes with formability for edge returns, corner bends, and complex profiles. Weldability supports the fabrication of assemblies that integrate multiple formed components into a single installation-ready unit.

Medium plate from 6.0mm to 50mm covers the pressure vessel, storage tank, and structural fabrication that forms the backbone of chemical plant and heavy industrial construction. Tank shell courses, vessel heads, tube sheets, structural gusset plates, and equipment support frames are cut, formed, and welded from plate in this thickness range. The heavier gauges within this band—20mm and above—are typically processed on heavy-duty plate processing equipment: plasma or oxy-fuel cutting tables, heavy plate rolls, and large-tonnage press brakes.

Heavy plate from 50mm to 500mm represents the extreme end of stainless steel flat product capability. Pressure vessel shells for high-pressure reactors, tube sheets for large shell-and-tube heat exchangers, structural base plates for heavy equipment, and massive flanges and forgings are machined from ultra-heavy plate. At these thicknesses, the plate is typically supplied as discrete pieces rather than coil, and processing involves machining, drilling, and welding rather than the sheet metal forming operations associated with thinner gauges. The availability of SUS304 plate at thicknesses up to 500mm enables the fabrication of equipment that would otherwise require forged rings or cast components, with the superior structural integrity and inspectability of wrought plate product.

Length and Width: Flexible Dimensions for Efficient Fabrication

The length range of 1000mm to 12000mm and width range of 100mm to 1500mm provide the dimensional flexibility required for efficient fabrication across diverse construction and industrial applications. The ability to customize dimensions within these ranges ensures that the ordered material matches the specific requirements of the fabrication, minimizing the cut-off waste that occurs when standard stock sizes are trimmed to component dimensions.

For architectural panel systems, sheets are often ordered at the exact panel width required by the façade module, eliminating the ripping cuts that would otherwise be necessary and producing panel blanks ready for edge forming. For tank and vessel fabrication, plate lengths can be matched to the developed shell course dimensions, reducing the number of longitudinal and circumferential welds required. For structural fabrication, plate widths can be ordered to match flange and web dimensions for built-up sections, or to provide the exact blank size for complex profiled components.

The extended maximum length of 12 meters is particularly valuable for minimizing welded joints in long continuous runs—roofing sheets that run from eave to ridge without a transverse lap joint, tank shell courses with fewer vertical welds, and architectural panel systems with uninterrupted horizontal lines. The reduction in joint count translates directly to reduced fabrication cost, fewer inspection requirements, and improved visual continuity in exposed applications.

Construction and Chemical Industry Applications

In construction, SUS304 hot rolled sheet and plate serve both the visible and the structural functions of buildings. Architectural cladding, roofing, and façade panels in 0.5mm to 3.0mm gauge provide the building envelope with a corrosion-resistant, aesthetically versatile surface that requires no protective coatings, no scheduled repainting, and minimal maintenance. Structural connections—shear plates, gusset plates, base plates, and anchor plates—fabricated from heavier gauge SUS304 plate transfer structural loads through connections that resist the corrosion that would compromise carbon steel connections in exposed or humid environments. Interior applications including elevator cabins, lobby wall panels, column covers, handrail systems, and decorative feature elements exploit SUS304's ability to accept a wide variety of surface finishes from utilitarian No.1 to mirror-polished, brushed, and embossed decorative textures.

In the chemical industry, SUS304 plate provides the pressure-containing and corrosion-resisting boundary for storage tanks, pressure vessels, and process equipment handling a broad range of chemical products. Organic chemicals—solvents, monomers, polymers, and finished chemical products—are routinely stored and processed in SUS304 equipment. Inorganic chemicals at moderate concentrations and temperatures—caustic soda, phosphoric acid, and various salt solutions—are within the grade's corrosion resistance capability, subject to verification against the specific chemical, concentration, and temperature conditions. The material's weldability supports the full-penetration butt and fillet welds required for pressure vessel code construction, and its formability enables the rolling of shell courses and the pressing of formed heads.

Quality Documentation and Supply

Every shipment of JIS SUS304 hot rolled sheet and plate is accompanied by material certification to EN 10204 3.1, documenting the full chemical analysis—chromium, nickel, carbon, and residual elements—in accordance with JIS G4304 requirements, together with mechanical properties including tensile strength, yield strength, elongation, and hardness. The certification confirms JIS conformance and provides full traceability from the delivered plate to the originating cast and heat number.

Plates and sheets are marked with the grade designation (SUS304), heat number, and dimensional identification per standard practice. Surface inspection verifies that the material is free from defects—laminations, slivers, rolled-in scale, and excessive pitting—that would compromise fabrication or service performance. Packaging with interleaving protection, edge guards, and weatherproof wrapping ensures that the material arrives at the fabrication shop or construction site in the condition required for immediate use.

If you have a specific construction project, tank or vessel specification, architectural finish requirement, or dimensional need to discuss, I can confirm that JIS SUS304 hot rolled sheet or plate at the required gauge is available, advise on thickness selection for structural or pressure-retaining applications, and prepare a quotation for the dimensions, quantities, and delivery schedule your project requires.