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.

347 is a niobium-stabilized austenitic steel similar to 321 but with better high-temperature strength. It prevents intergranular corrosion after exposure to high temperatures.
Key Properties
Stabilization: Niobium prevents chromium carbide precipitation.
High Temp: Good mechanical properties up to 800°C.
Weldability: Excellent for heavy gauge welding without post-weld annealing.
Ductility: Good formability for complex high-temp parts.
Common Applications
Aerospace: Exhaust manifolds and firewalls.
Refining: Catalytic cracking equipment and expansion joints.
Boilers: Superheater tubes and high-temp piping.
Automotive: Thermal oxidizers and exhaust components.

302 is an austenitic stainless steel similar to 304 but with slightly higher carbon content. It offers good corrosion resistance and excellent formability, often used in springs and general fabrication.
Key Properties
Corrosion: Good resistance to oxidation and mild acids, similar to 304.
Formability: Excellent ductility for deep drawing and bending.
Strength: Higher carbon provides slightly higher strength than 304.
Weldability: Good weldability using standard methods.
Common Applications
Springs: High-quality springs and wire forms.
Fasteners: Bolts, nuts, and screws.
Kitchenware: Sinks, cookware, and food processing equipment.
Architecture: Decorative trim and building facades.

405 is a lower-cost ferritic stainless steel with aluminum addition instead of titanium. It offers moderate corrosion resistance and good weldability, often used where high polish is not required.
Key Properties
Weldability: Better weldability than other ferritic grades due to aluminum.
Corrosion: Moderate resistance to atmospheric corrosion and fresh water.
Cost: Economical alternative to 430 for less demanding uses.
Ductility: Good formability for simple shapes.
Common Applications
Industrial: Drip pans, quench tanks, and annealing boxes.
Automotive: Underbody components and non-visible trim.
Construction: Roofing and siding for agricultural buildings.
General: Parts requiring moderate heat and corrosion resistance.

409 is a titanium-stabilized ferritic stainless steel designed specifically for automotive exhaust systems. It offers good oxidation resistance at high temperatures and excellent formability.
Key Properties
Heat Resistance: Resists oxidation in exhaust gas environments up to 600-700°C.
Weldability: Titanium stabilization improves weld zone toughness.
Cost: Lower cost than austenitic grades like 304/409M.
Formability: Good ductility for complex exhaust shapes.
Common Applications
Automotive: Exhaust manifolds, catalytic converter shells, and tailpipes.
Agriculture: Grain dryer components and silo vents.
Construction: Heat exchangers and HVAC ducting.
Industrial: Conveyor belts for heat treatment.

302HQ strip is an austenitic alloy optimized for cold heading. Modified from 302/304 grades, it features a low work-hardening rate, allowing severe deformation without cracking.
Key Properties
Cold Heading: "HQ" means High Quality for heading. Excellent ductility allows significant deformation without fracturing, superior to standard 304 for fasteners.
Strength: Soft enough for forming but achieves high tensile strength after cold working.
Corrosion: Similar to AISI 304; resists oxidation and rust in mild environments.
Magnetism: Non-magnetic when annealed; slightly magnetic after cold work.
Common Applications
Widely used for room-temperature shaping:
Fasteners: Screws, bolts, nuts, rivets.
Electronics: Pins, connectors, lead frames.
Auto Parts: High-strength precision components.
Household: Zippers, hooks, formed accessories.