| Material Grade | Austenitic stainless steel, Type 304 | Provides a combination of corrosion resistance, formability, weldability, and general structural strength. | Exposure to chlorides, acids, stagnant moisture, and elevated temperatures can reduce corrosion resistance. | Suitable for many general-purpose indoor and moderately corrosive environments. |
| Typical Applications | Frames, brackets, supports, guards, rails, racks, platforms, and equipment bases | The equal-leg or unequal-leg profile provides efficient support, edge reinforcement, and connection surfaces. | Actual load, vibration, impact, joint design, and installation quality determine structural durability. | Confirm the required leg size, thickness, span, and connection method through engineering calculations. |
| Food and Commercial Facilities | Kitchen fixtures, shelving, preparation areas, cabinets, and sanitary support frames | The smooth, cleanable surface and relatively low maintenance requirement make 304 suitable for many hygienic environments. | Salt, cleaning chemicals, food residues, crevices, and poor drainage can cause staining or localized corrosion. | Use appropriate cleaning practices and avoid prolonged contact with chlorinated chemicals. |
| Architectural and Interior Uses | Trim, partitions, display structures, handrails, edge protection, and decorative frameworks | 304 stainless steel maintains a clean metallic appearance and can be supplied with polished, brushed, or mill finishes. | Surface scratches, iron contamination, fingerprints, abrasion, and exposure to pollutants affect appearance. | Select the surface finish according to the required appearance and cleaning frequency. |
| Nominal Chemical Composition | Chromium: 18.0–20.0%; Nickel: 8.0–10.5%; Carbon: maximum 0.08% | Chromium supports the passive oxide film, while nickel stabilizes the austenitic structure and improves formability. | Welding, heat exposure, surface contamination, and chemical attack can affect the protective passive film. | Composition limits may vary slightly with the applicable material standard and product form. |
| Minimum Tensile Strength | Approximately 515 MPa for typical annealed sheet or plate specifications | Indicates the approximate stress level associated with ultimate tensile failure in the referenced product standard. | Cold working, forming, welding, temperature, section geometry, and defects influence actual component strength. | Do not use tensile strength alone for design; check yield strength, buckling, and connection capacity. |
| Minimum Yield Strength | Approximately 205 MPa for typical annealed sheet or plate specifications | Provides a reference for estimating the stress level at which permanent deformation may begin. | Angle dimensions, unsupported length, local buckling, residual stress, and loading direction are critical. | Structural calculations should use values required by the applicable design code. |
| Formability and Weldability | Generally good; commonly fabricated by cutting, bending, drilling, and welding | Supports efficient fabrication of brackets, frames, supports, and custom assemblies. | Excessive heat input, distortion, weld contamination, and improper post-weld cleaning may reduce corrosion resistance. | Use clean tools, suitable filler metal, controlled heat input, and thorough removal of heat tint. |
| Corrosion Resistance | Good in fresh water, indoor atmospheres, and many mild industrial environments | The chromium-rich passive film provides protection when the surface is clean and exposed to oxygen. | Chloride ions, coastal salt spray, hydrochloric acid, crevice conditions, and deposits may cause pitting or crevice corrosion. | For severe chloride or marine exposure, a higher-alloy stainless grade may be more appropriate. |
| Temperature Exposure | Performance depends strongly on temperature, atmosphere, load, and exposure duration | 304 can retain useful properties over a broad temperature range, but strength and oxidation behavior change with heat. | High temperature can reduce strength, cause scaling, promote distortion, and increase sensitization risk after welding. | Evaluate both short-term and continuous operating temperatures before selection. |
| Surface Condition | Mill finish, brushed finish, polished finish, or mechanically cleaned surface | A clean, smooth surface generally reduces dirt retention and improves visual uniformity. | Iron particles from carbon-steel tools, rough scratches, weld discoloration, and deposits can initiate surface corrosion. | Use dedicated stainless-steel tools where practical and clean the surface after fabrication. |
| Drainage and Joint Design | Open, accessible joints with minimal water-trapping areas | Good drainage limits the time that moisture, salts, and contaminants remain on the surface. | Crevices, lap joints, blocked channels, tight corners, and stagnant water accelerate localized corrosion. | Design for drainage, inspection, ventilation, and easy cleaning. |
| Maintenance Requirements | Routine cleaning with clean water and a compatible mild detergent | Regular removal of salt, dirt, chemical residue, and embedded particles helps preserve the passive film. | Harsh abrasives, bleach-based cleaners, strong acids, and prolonged contamination can damage the surface. | Rinse thoroughly and dry the angle after cleaning, especially in coastal or humid areas. |
| Service-Life Assessment | No universal service-life value; project-specific evaluation is required | Durability depends on the combined effects of material grade, thickness, loading, environment, fabrication, and maintenance. | Unexpected corrosion, overload, fatigue, impact, poor welds, and inadequate drainage can shorten service life. | Inspect periodically for pitting, deformation, cracking, loose fasteners, and coating or surface damage. |