Type 304 Angles

Type 304 is the most widely used austenitic stainless steel, also known as "18-8" for its typical composition of 18% chromium and 8% nickel. This composition provides exceptional resistance to a wide range of atmospheric and chemical exposures. As an angle, Type 304 provides structural rigidity in two directions, making it a fundamental component for building frames, brackets, and supports. The 90-degree profile is ideal for corner reinforcement and creating strong, straight edges in fabricated assemblies. The material's inherent corrosion resistance and clean finish also make it a popular choice for architectural trim, food processing equipment framework, and applications where both strength and aesthetic appearance are required.

The 18-8 chromium-nickel composition provides robust resistance to atmospheric corrosion, food acids, and organic chemicals. In the annealed condition, 304 angle is non-magnetic and cannot be hardened by heat treatment, making it ideal for forming and welding operations. Strength can only be increased through cold working.

Our angles are produced through hot rolling, with surface finishes ranging from mill finish to pickled and annealed (PA). Each angle is straight, dimensionally accurate to ASTM A276 tolerances, and fully traceable to the original mill heat number.

Our Quality Guarantee

Every order of 304 angles comes with full traceability. We provide MTR (Mill Test Report) with chemical composition and mechanical properties for each batch, traceable to the original mill heat number. Our defect rate has been under 0.02% over the past 3 years - if any angle fails to meet ASTM A276 standards, we replace it free of charge.

For stock sizes, we ship within 48 hours. Custom production orders ship within 7-10 business days. Free samples available - test quality before committing to a bulk order.

⚠️ Reference Data Only: Values shown are per ASTM A276 / A479 standards. For critical applications, please contact us to verify specifications or request a Mill Test Report (MTR) for your specific batch.

Chemical Composition (%)

Mechanical Properties (Room Temperature, Annealed, Longitudinal)

Available Sizes & Weights (Equal Leg Angles)

Standard Length: 20 ft (6m). Custom lengths available. Larger sizes available upon request.

Applicable Standards

Available Finishes

Angle Tolerances (per ASTM A276 for Shapes)

Choosing the right stainless steel grade depends on your corrosion environment, welding requirements, and budget. Below is a direct comparison of the three most common austenitic grades used for angle and structural applications.

304 vs 304L vs 316L Comparison

Which One Should You Choose?

Choose 304 for most general applications - structural supports, brackets, architectural trim, and food processing frames. It offers the best balance of performance and cost for the widest range of applications.

Choose 304L when extensive welding is required on thick sections. The lower carbon content (≤0.035%) prevents carbide precipitation in the heat-affected zone, eliminating the need for post-weld annealing to restore corrosion resistance.

Choose 316L for coastal environments, chemical processing, pharmaceutical, or marine applications where exposure to chlorides makes pitting and crevice corrosion a concern. The addition of 2-3% molybdenum provides significantly improved resistance to chloride-induced corrosion.

Other Related Stainless Steel Grades for Reference

Architectural & Structural

Brackets, corner guards, trim, lintels, and support frames where corrosion resistance is needed. 304's natural weathering resistance provides a service life of 30+ years in most urban and suburban environments.

Food & Beverage Processing

Framework for equipment, conveyor systems, and sanitary supports due to its non-reactive surface. The clean finish prevents bacterial adhesion and meets FDA food contact requirements under 21 CFR 175.300.

General Fabrication

Frames for workbenches, carts, shelving units, and machine bases in workshops and industrial settings. The 90-degree angle profile provides ready-to-use structural rigidity without additional forming.

Petrochemical & Process Industry

Pipe supports, grating substructures, skid base frames, walkway supports, and instrumentation brackets. 304 provides cost-effective corrosion resistance in mild chemical environments where organic acids, alcohols, and mild oxidizing agents are present.

Medical Equipment (Non-Implant)

Equipment cart frames, table supports, instrument stands, and lab furniture. 304's cleanability, sterilization resistance (autoclave, chemical), and non-reactive surface make it suitable for non-implantable medical and pharmaceutical facility applications.

Automotive & Transportation

Custom framework, mounting brackets, and supports for aftermarket parts and trailer components. 304 resists intermittent road salt exposure and provides lasting performance in under-vehicle and structural applications.

Marine & Coastal (With Caution)

Non-structural supports, cleats, and trim in freshwater environments. Note: 304 has limited resistance to continuous saltwater exposure. For components below the waterline or in constant chloride spray, 316L grade should be used instead to prevent pitting corrosion.

Sculptural & Artistic

Armatures and structural elements in artwork requiring longevity and weather resistance. The clean, consistent surface finish of 304 angle makes it a preferred material for both indoor and outdoor sculptural installations.

Machining

Type 304 has fair machinability but is prone to work hardening. For best results, use sharp tooling, slow speeds, heavy feeds, and a quality cutting lubricant. Chip breakers are recommended as the material produces tough, stringy chips.

Recommended Parameters (Carbide Tooling):

Tooling: Use sharp C-2 or C-3 grade carbide inserts with positive rake angles (5° or more). TiAlN or AlTiN coated grades improve tool life. Avoid high-speed steel (HSS) tools for production work.

Coolant: Flood coolant with water-soluble oil (5-10% emulsion) is essential. The low thermal conductivity of 304 requires adequate cooling to prevent work hardening and maintain surface finish.

Key Tips: Never let the feed rate drop below 0.003 in/rev - a light feed causes the tool to rub against the work-hardened surface rather than cut. Use chip breakers to control long, stringy chips. Maintain constant cutting load; avoid stopping the tool on the workpiece surface.

Welding

This alloy exhibits excellent weldability using all common fusion and resistance methods. AWS E/ER308L filler metal is recommended to maintain corrosion resistance in the heat-affected zone by preventing carbide precipitation.

Preheat: Not required for sections under 1" (25mm) thickness. For heavier sections, a slight preheat of 200-300°F (93-149°C) may help reduce thermal stress. Interpass temperature should not exceed 350°F (175°C).

Post-Weld Treatment: Post-weld annealing is not typically required to restore corrosion resistance for most applications. For 304L, the low carbon content (≤0.035%) eliminates the risk of sensitization in the heat-affected zone.

Heat Treatment

Important: As an austenitic stainless steel, 304 has no phase transformation and cannot be hardened by heat treatment. Strength can only be increased through cold working.

Cold Forming

304 angle can be bent and formed in the annealed condition. It offers good ductility (40% elongation minimum in 2") but work hardens more rapidly than carbon steel. For complex forming sequences, intermediate annealing may be needed between stages to restore ductility.

Forming Notes: Use fully annealed material for bending operations. Account for springback - 304 typically rebounds more than carbon steel in bending. For heavy forming, consider hot forming at 1700-2100°F (925-1150°C) to reduce cracking risk.

Q: What is the difference between 304 angle and 304 flat bar?

A: Angle has an L-shaped cross-section providing structural rigidity in two directions, ideal for frames, brackets, and corner reinforcement. Flat bar has a rectangular cross-section, used when one-directional strength or a flat mounting surface is required. They serve different structural purposes and are selected based on the specific load requirements of your application.

Q: Can 304 stainless steel angle rust?

A: 304 is highly resistant to atmospheric corrosion, food acids, and most organic chemicals. However, in environments with high chloride content - such as coastal salt spray, deicing salts, or chlorinated cleaning agents - 304 can develop surface pitting or staining. This surface discoloration is typically superficial and can be removed by passivation or acid cleaning. For continuous marine or chloride exposure, 316L grade is recommended for its molybdenum-enhanced pitting resistance.

Q: Is 304 stainless steel angle magnetic?

A: In its annealed condition, 304 is essentially non-magnetic (relative permeability μ ≤ 1.02). However, cold working - including bending, cutting, or forming - can induce partial transformation to martensite, producing slight magnetism. This is a normal characteristic of austenitic stainless steel and does not affect corrosion resistance or mechanical properties.

Q: What surface finishes do you offer for 304 angles?

A: We supply four standard finishes: Hot Rolled (HR) - as-rolled surface, suitable for general structural use; Pickled & Annealed (PA) - chemically cleaned, scale-free surface for food processing and architectural applications; Mill Finish - standard as-rolled surface for general fabrication; and Polished (#4 finish) - brushed finish for architectural trim, food contact, and decorative uses. Contact us for specific finish requirements.

Q: What is the minimum order quantity (MOQ)?

A: For stock sizes, our MOQ is typically 500 lbs (approx. 225 kg) per size per grade. For non-stock or custom sizes, MOQ varies by availability. Contact our sales team for a quote specific to your size, quantity, and delivery requirements.

Q: Can you cut angles to custom lengths?

A: Yes. Our standard length is 20 ft (6m). We can precision-cut to any custom length with a typical tolerance of ±1/8" (±3mm). We also offer secondary services including punching, drilling, and welding to your specifications.

Q: Do you provide Material Test Reports (MTR)?

A: Yes. Every order of 304 angles is accompanied by a Mill Test Report (MTR) certifying the chemical composition and mechanical properties per ASTM A276, traceable to the original heat number and mill. Third-party inspection by SGS, TÜV, or BV can also be arranged upon request (additional charges apply).

Q: What tolerances do you hold on 304 angles?

A: Per ASTM A276 for shapes, our standard tolerances are: ±0.005" for leg sizes up to 1", ±0.008" for leg sizes over 1" to 2", ±0.010" for leg sizes over 2" to 3", and ±0.015" for leg sizes over 3" to 4". Tighter tolerances can be negotiated for custom orders.

Q: Can I get a sample before ordering?

A: Yes. We provide free samples so you can evaluate surface quality, dimensional accuracy, and weldability before committing to a production order. You only need to cover the shipping cost. Contact us with your required size, finish, and delivery address.

Q: What is the maximum operating temperature for 304 angle?

A: 304 can be used at continuous service temperatures up to approximately 1650°F (900°C) in air, and intermittent service up to 1500°F (815°C). Beyond these temperatures, significant oxidation and scaling may occur. For sustained high-temperature applications, consider 310S or 321 grades which offer superior high-temperature performance.

Q: Are 304 and 18-8 stainless steel the same thing?

A: "18-8" is an industry shorthand referring to the family of austenitic stainless steels containing approximately 18% chromium and 8% nickel. This family includes grades 302, 304, 304L, and others. Grade 304 (with its standard composition of 18-20% Cr and 8-10.5% Ni) is the most common 18-8 grade. While the terms are sometimes used interchangeably in practice, "18-8" is not a formal ASTM or SAE grade designation - specifications and mechanical properties should always reference the specific ASTM grade (e.g., 304 per ASTM A276).

Q: What shipping and payment terms do you support?

A: We support FOB, CIF, CFR, and EXW trade terms. Standard payment terms are T/T (telegraphic transfer, 30% deposit with 70% balance before shipment) and L/C (irrevocable letter of credit at sight). Long-term contract pricing is available for volume commitments. Contact our sales team to discuss your specific logistics requirements.