| Product Definition | An L-shaped structural or architectural section manufactured from austenitic stainless steel grade 304. It is available as equal-leg or unequal-leg angle and may be hot rolled, cold formed, or laser welded. | Common variants include 304, 304L, and 304H. | Confirm whether the required product is structural angle, architectural trim, or fabricated angle because manufacturing method, tolerances, and surface finish can differ. |
| Typical Chemical Composition | Chromium: 18.0–20.0%; Nickel: 8.0–10.5%; Manganese: maximum 2.0%; Silicon: maximum 1.0%; Carbon: maximum 0.08%; Iron: balance. | 304L permits carbon up to 0.03%; 304H generally requires carbon of 0.04–0.10% for elevated-temperature service. | Actual limits depend on the applicable standard, such as ASTM, EN, or JIS. Chemical composition should be checked against the material test certificate. |
| Metallurgical Structure | Austenitic stainless steel with a face-centered cubic crystal structure. It is generally non-magnetic in the annealed condition. | Cold working can increase magnetic response because deformation may produce some martensitic transformation. | Magnetism alone is not a reliable grade-identification method. Use positive material identification or certified chemical analysis when grade verification is important. |
| Minimum Tensile Strength | Typically 515 MPa under ASTM A276/A276M requirements for many 304 bar and angle products. | 304L commonly has a minimum tensile strength of approximately 485 MPa under ASTM A276/A276M, while 304H requirements may vary by product standard. | Minimum mechanical values vary with product form, thickness, heat treatment, and governing specification. |
| Minimum Yield Strength | Typically 205 MPa at 0.2% offset under ASTM A276/A276M requirements for many 304 products. | 304L commonly has a minimum yield strength of approximately 170 MPa under ASTM A276/A276M. | For load-bearing applications, design calculations should use the applicable standard and certified thickness-specific values. |
| Elongation | Typically a minimum of 40% in 50 mm for many annealed 304 products under ASTM A276/A276M. | 304L commonly provides high ductility, often with a minimum elongation of about 40%, depending on the product specification. | High ductility supports bending, forming, and fabrication, but the actual result depends on processing and test direction. |
| Density | Approximately 7.9–8.0 g/cm³, commonly calculated as about 7,930 kg/m³. | 304, 304L, and 304H have broadly similar density values. | Use the supplier’s certified mass-per-metre table for accurate shipping weight and structural calculations. |
| Elastic Modulus | Approximately 193 GPa at room temperature. | The modulus is broadly similar across the 304 family and is lower than that of typical carbon steels. | Deflection calculations should account for stainless steel’s elastic modulus rather than using carbon-steel values. |
| Thermal Conductivity | Approximately 16 W/m·K at room temperature. | Similar values apply to 304L; elevated-temperature data should be taken from the relevant design standard. | Lower thermal conductivity than carbon steel can affect welding heat flow and thermal expansion design. |
| Coefficient of Thermal Expansion | Approximately 17.2 × 10−6/K over a typical room-temperature range. | 304 and 304L generally have comparable thermal expansion behavior. | Allow for thermal movement in long angles, cladding supports, pipe racks, and outdoor assemblies. |
| Corrosion Resistance | Good general resistance to atmospheric corrosion, moisture, food-processing environments, and many mild chemicals. | 304L offers the same basic corrosion resistance as 304; 316L is normally preferred where chloride exposure is severe. | 304 is not immune to pitting or crevice corrosion in seawater, concentrated chlorides, or stagnant wet conditions. |
| Intergranular Corrosion Performance | Standard 304 can become susceptible to sensitization after prolonged exposure to approximately 450–850°C. | 304L reduces the risk because of its lower carbon content; stabilized grades such as 321 may be selected for certain high-temperature welding conditions. | 304L is often preferred for welded assemblies that will not be solution annealed after fabrication. |
| Weldability | Generally excellent with common processes including TIG, MIG, and resistance welding. | 304L is widely selected for welded construction because it reduces carbide precipitation risk. | Use suitable stainless filler metal, clean tools dedicated to stainless steel, and proper post-weld cleaning to restore corrosion resistance. |
| Formability and Machinability | Excellent cold formability, but it work-hardens rapidly during cutting, drilling, and forming. | 304L behaves similarly; cold-worked sections may show increased strength and some magnetic response. | Use sharp tooling, adequate feed rates, rigid setups, and controlled heat input during machining. |
| Common Surface Finishes | Mill finish, No. 1, 2B, No. 4 brushed, satin, polished, and bead-blasted finishes are commonly specified depending on manufacturing route. | Cold-formed or fabricated angles may require additional grinding, polishing, or passivation. | Specify surface roughness, grain direction, protective film, weld blending, and allowable visual imperfections. |
| Typical Angle Configurations | Equal-leg angle, unequal-leg angle, slotted angle, perforated angle, and custom welded angle. | Equal-leg angles are commonly used for frames and supports; unequal-leg angles are useful where one leg must provide greater bearing or attachment area. | Confirm leg length, thickness, inside radius, straightness, squareness, and cut length before ordering. |
| Applicable Product Standards | Common references include ASTM A276/A276M for stainless steel bars and shapes, ASTM A484/A484M for general requirements, and ASTM A240/A240M for stainless sheet and plate used in fabrication. | European projects may reference EN 10088; Japanese projects may reference JIS G4303 or related product standards. | The standard must match the product form. Do not assume a plate standard automatically covers a hot-rolled structural angle. |
| Dimensional Tolerances | Controlled by the selected product standard and manufacturing process; hot-rolled, cold-formed, and welded angles can have different tolerances. | Custom fabricated angles may be governed by a fabrication drawing rather than a standard rolled-shape table. | Request dimensional inspection data for leg length, thickness, angle squareness, length, radius, and straightness. |
| Common Applications | Food-processing equipment, architectural trim, handrails, tanks, hygienic frames, marine-adjacent structures, machinery guards, shelving, and general fabrication. | 304L is especially common in welded frames, vessels, and process equipment. | For high-chloride, coastal splash-zone, or chemical environments, compare 304 with 316/316L before final selection. |
| Worldwide Sourcing Regions | 304 stainless steel angles are commonly produced and distributed across Asia, Europe, North America, South America, and the Middle East. | Availability depends on section size, surface finish, standard, minimum order quantity, and whether the angle is rolled or fabricated. | Compare suppliers using the same grade designation, standard, dimensions, finish, tolerance class, certification package, and delivery terms. |
| Quality Documents to Request | Material test certificate, chemical composition, tensile and yield results, elongation, heat number, dimensional inspection report, and surface-finish details. | For welded angles, request welding procedure information, weld inspection records, and passivation or pickling documentation where applicable. | For regulated projects, also verify third-party inspection, traceability, country-of-origin documentation, and applicable compliance declarations. |
| Important Selection Limitation | 304 provides strong general-purpose corrosion resistance but may suffer pitting, crevice corrosion, or stress-corrosion cracking in aggressive chloride environments. | Consider 316L, duplex stainless steel, or a higher-alloy grade when chloride concentration, temperature, or chemical exposure exceeds 304 capability. | Final material selection should be based on exposure conditions, design loads, temperature, fabrication method, cleaning regime, and applicable engineering codes. |
