Stainless steel flat steel can be composed of various stress-bearing components according to different structural needs, and can also be used as connectors between components. It is widely used in various building structures and engineering structures, such as house beams, bridges, transmission towers, lifting and transportation machinery, ships, industrial furnaces, reaction towers, container racks and warehouse shelves, etc.

Stainless steel square tube is a hollow long steel material. It is called a square tube because its cross section is square. They are widely used as pipelines for transporting fluids, such as oil, natural gas, water, coal gas, steam, etc. In addition, they are lighter in weight when the bending and torsional strength are the same, so they are also widely used in the manufacture of mechanical parts and engineering structures.

202 is an austenitic stainless steel with high manganese and nitrogen, serving as a cost-effective alternative to 304. It offers good formability and moderate corrosion resistance for indoor and general-purpose applications.
Key Properties
Cost Efficiency: Lower nickel content makes it cheaper than 304.
Strength: High work-hardening rate provides excellent strength after cold forming.
Corrosion: Suitable for dry indoor environments; less resistant to chlorides than 304.
Formability: Good ductility for stamping, bending, and drawing.
Common Applications
Kitchenware: Sinks, cookware, and utensils for indoor use.
Architecture: Indoor decorative panels, window frames, and handrails.
Automotive: Interior trim and non-structural components.
Furniture: Tables, chairs, and shelving units.

301 is a metastable austenitic stainless steel with a high work-hardening rate. It can achieve very high strength and hardness through cold rolling, making it ideal for springs and structural components.
Key Properties
Work Hardening: Extremely high work-hardening rate for maximum strength.
Strength: Can achieve very high tensile strength through cold rolling.
Corrosion: Good resistance in mild atmospheres; slightly less than 304.
Magnetism: Becomes slightly magnetic after cold working.
Common Applications
Springs: High-strength springs, clips, and fasteners.
Railway: Train car structural parts and underframes.
Automotive: Wheel covers and structural reinforcements.
Construction: Roofing and wall panels requiring strength.

301L is a low-carbon variant of 301, optimized for excellent formability and high work-hardening rate. It is widely used in railway vehicles and structural applications requiring strength after forming.
Key Properties
Work Hardening: Very high work-hardening rate for increased strength after cold forming.
Formability: Improved ductility compared to standard 301 for complex shapes.
Corrosion: Similar to 304 in mild atmospheres.
Weldability: Good weldability due to low carbon content.
Common Applications
Railway: Train car bodies, structural frames, and interior panels.
Automotive: Structural reinforcements and seat frames.
Construction: Roofing, wall cladding, and structural components.
Springs: High-strength springs and clips.

321 is a titanium-stabilized austenitic stainless steel similar to 304 but with improved intergranular corrosion resistance after exposure to high temperatures. It is ideal for welding and high-temperature service.
Key Properties
Stabilization: Titanium prevents chromium carbide precipitation during welding.
High Temp: Good oxidation resistance up to 900°C.
Weldability: Excellent for heavy gauge welding without post-weld annealing.
Corrosion: Similar to 304 in mild environments.
Common Applications
Aerospace: Exhaust manifolds, firewalls, and aircraft components.
Refining: Catalytic cracking equipment and expansion joints.
Boilers: Superheater tubes and high-temperature piping.
Chemical: Welded vessels and heat exchangers.

310S is a high-chromium, high-nickel austenitic stainless steel designed for high-temperature applications. It offers excellent oxidation resistance and strength at elevated temperatures up to 1150°C.
Key Properties
Heat Resistance: Outstanding oxidation resistance up to 1150°C (intermittent).
Strength: Retains good mechanical properties at high temperatures.
Corrosion: Good general corrosion resistance in mild environments.
Formability: Excellent ductility for high-temp component fabrication.
Common Applications
Furnace Parts: Heat exchangers, radiant tubes, and annealing boxes.
Kiln Linings: Refractory supports and conveyor belts.
Automotive: Exhaust manifolds and catalytic converter shells.
Power Generation: Boiler components and superheater tubes.

904L is a high-alloy austenitic stainless steel with very high chromium, nickel, molybdenum, and copper content. It offers superior corrosion resistance in highly aggressive environments, especially sulfuric acid.
Key Properties
Corrosion: Exceptional resistance to sulfuric acid, phosphoric acid, and chlorides.
Pitting Resistance: High PREN (Pitting Resistance Equivalent Number) value.
Weldability: Good weldability with standard methods.
Formability: Excellent ductility for deep drawing and forming.
Common Applications
Chemical: Sulfuric acid storage tanks, heat exchangers, and piping.
Pharmaceutical: Reaction vessels and processing equipment.
Marine: Seawater cooling systems and offshore components.
Pollution Control: Flue gas desulfurization equipment.

410 is a general-purpose martensitic stainless steel that can be heat-treated to achieve high hardness and strength. It offers moderate corrosion resistance and is widely used in cutlery and industrial components.
Key Properties
Hardness: Can be hardened by heat treatment to achieve high tensile strength.
Wear Resistance: Excellent resistance to abrasion and wear after hardening.
Corrosion: Moderate resistance to mild atmospheres and fresh water.
Machinability: Good machinability in the annealed condition.
Common Applications
Cutlery: Knives, scissors, and surgical instruments.
Fasteners: Bolts, nuts, and screws requiring high strength.
Pumps & Valves: Shafts, bushings, and valve seats.
Automotive: Pump parts and turbine blades.

2205 is the most widely used duplex stainless steel, combining the benefits of austenitic and ferritic structures. It provides excellent resistance to stress corrosion cracking and high mechanical strength.
Key Properties
Duplex Structure: Balanced austenite-ferrite microstructure for toughness.
Corrosion: Good resistance to chlorides and organic acids.
Strength: Yield strength is twice that of 304/316, allowing thinner designs.
Cost: More economical than super duplex grades like 2507.
Common Applications
Chemical Processing: Heat exchangers, pressure vessels, and storage tanks.
Oil & Gas: Flow lines, manifolds, and process piping.
Pulp & Paper: Digesters and bleaching equipment.
Marine: Ship hulls and cargo tanks for chemical tankers.

2507 is a super duplex stainless steel with high chromium, molybdenum, and nitrogen content. It offers exceptional resistance to chloride stress corrosion cracking and pitting, making it ideal for the most aggressive environments.
Key Properties
Corrosion: Superior resistance to chlorides, acids, and seawater.
Strength: High yield strength, approximately double that of austenitic grades.
Durability: Excellent resistance to erosion and abrasion.
Weldability: Good weldability with proper procedures.
Common Applications
Oil & Gas: Subsea pipelines, risers, and offshore platform components.
Desalination: High-pressure reverse osmosis systems and heat exchangers.
Chemical: Tanks and piping for aggressive acids like sulfuric and phosphoric.
Marine: Propeller shafts and pump impellers in seawater.

403 is a general-purpose martensitic stainless steel. It can be heat-treated to achieve high hardness and strength, making it suitable for turbine blades and cutlery.
Key Properties
Hardness: Can be hardened by heat treatment to high levels.
Strength: High tensile strength and wear resistance.
Corrosion: Moderate resistance; less than ferritic/austenitic grades.
Machinability: Good machinability in annealed condition.
Common Applications
Power Generation: Steam turbine blades and buckets.
Cutlery: Knives, scissors, and surgical instruments.
Fasteners: Bolts and nuts requiring high strength.
Pumps: Shafts and valve parts subject to wear.