Type 304 Expanded Metal Sheets
About Type 304 Expanded Metal Sheets
Type 304 expanded stainless steel sheet offers excellent corrosion resistance and a high strength-to-weight ratio. Base material conforms to ASTM A240. Ideal for grates and security screens. Los Angeles stock.
Quick Facts
- Material: Type 304 Stainless Steel
- ASTM Standard: A240 (Base Material)
- Available Sizes: Available in standard mill sizes
- Location: Los Angeles warehouse
- Services: Custom size, same-day pickup
Overview
Type 304 expanded metal is produced by slitting and stretching a solid stainless steel sheet, creating a rigid, non-raveling mesh with diamond-shaped openings. This process yields a high strength-to-weight ratio and allows for the free passage of air, light, and liquid. The inherent properties of Type 304 stainless steel, including its excellent resistance to atmospheric corrosion and oxidation, are retained, making it durable for various environments.
The one-piece construction of expanded metal ensures structural integrity without welds or joints that can fail under stress. Its textured, slip-resistant surface is a key benefit for safety applications like walkways, catwalks, and industrial flooring. The versatility of 304 expanded metal allows it to be easily formed, cut, and welded for custom fabrication projects, providing a functional and often decorative material for both industrial and architectural use.
Technical Specifications
Mechanical Properties (Base Material)
| Property | Value | Unit |
|---|---|---|
| Tensile Strength | 73,200 | PSI |
| Yield Strength | 31,200 | PSI |
| Elongation | 70 | % |
| Hardness | 123 | HB |
Chemical Composition (Base Material)
| Element | Percentage |
|---|---|
| Chromium (Cr) | 18.0 - 20.0% |
| Nickel (Ni) | 8.0 - 10.5% |
| Carbon (C) | 0.08% max |
| Manganese (Mn) | 2.0% max |
| Silicon (Si) | 0.75% max |
Applicable Standards
- ASTM A240: Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications.
Common Applications
- Industrial Flooring: Walkways, catwalks, and stairs - Slip-resistant surface and high strength.
- Security: Window guards, security fencing, and partitions - One-piece construction is difficult to breach.
- Filtration: Support screens for filter media - Allows fluid passage while providing structural integrity.
- Architecture: Building façades, sunscreens, and decorative panels - Modern aesthetic with light and air flow.
- HVAC: Equipment enclosures and vent covers - Protects components while enabling ventilation.
- Automotive: Grilles and protective screens for radiators - Combines protection with critical airflow.
- Safety Guards: Machinery and equipment guards - Provides a physical barrier without obstructing view or airflow.
- Marine: Access ramps and decking - Resists corrosion from moisture and salt spray.
Working with Type 304 Expanded Metal Sheets
Machining
Type 304 stainless is known for work-hardening. Use sharp tooling, heavy feeds, and low speeds to prevent glazing. A sulfurized cutting fluid is recommended. The expanded pattern may require support during machining operations to prevent vibration and ensure a clean cut.
Welding
Excellent weldability using common fusion and resistance techniques. TIG and MIG welding with AWS E/ER 308L filler metal is recommended to maintain corrosion resistance in the heat-affected zone. Post-weld annealing is not typically required for thin sections.
Finishing
Expanded 304 stainless steel has a standard mill finish. It can be electropolished for improved smoothness and corrosion resistance or passivated to remove free iron and enhance its protective oxide layer. Mechanical finishes like brushing are also possible.
Related Products
Frequently Asked Questions
Q: What is the difference between standard (raised) and flattened expanded metal?
A: Standard, or raised, expanded metal has a textured, diamond-pattern surface that provides excellent grip. Flattened expanded metal is cold-rolled after the expansion process, resulting in a smooth, flat surface. Bobco typically stocks standard expanded metal; contact us for flattened availability.
Q: Is 304 expanded metal suitable for outdoor use?
A: Yes, Type 304 stainless steel offers excellent resistance to atmospheric corrosion, making it well-suited for many outdoor applications, including guards, vents, and architectural panels. For marine or high-chloride environments, Type 316 expanded metal is recommended.
Q: How does expanded metal compare to perforated sheet?
A: Expanded metal is produced by slitting and stretching, creating no material waste and a high strength-to-weight ratio. Perforated metal is punched, removing material to create holes. Expanded metal's interconnected strands offer more structural rigidity than a perforated sheet of equivalent weight.
Stock & Custom Sizes
Available in standard mill sizes. Custom size available.
Same-day cutting and Los Angeles pickup available.
View Sizes & PricingNeed Type 304 Expanded Metal Sheets? Contact Bobco Metals for availability and Los Angeles pickup.
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