Stainless Steel 304 Round Bar

Product Description

Stainless Steel 304 Round Bar (also classified under cross-references like UNS S30400,DIN 1.4301, and SUS 304) is an austenitic chromium-nickel alloy. It is the most widely utilized stainless steel profile across machining, manufacturing, and structural fabrication due to its balanced mechanical profiling and robust chemical stability.

Below is an overview of its foundational engineering properties, supply conditions, and standard linear weight estimations.

Key Technical Specifications

• Chemical Composition: Contains 18% to 20% Chromium (Cr) and 8% to 10.5% Nickel (Ni) as its defining alloying elements, with a maximum carbon threshold of 0.08%.

• Mechanical Performance: Features a minimum Tensile Strength of 515 MPa (74,700 psi) and a minimum Yield Strength of 205 MPa (29,700 psi) at a 0.2% offset. It typically displays an elongation capacity of 35% to 40% and a maximum hardness of 201–215 Brinell (HB).

• Physical Parameters: Operates with a dense mass configuration of 8.0 g/cm³ (or 7.93 g/cm³ depending on processing variants) and holds a melting point threshold between 1400°C and 1450°C. It remains reliably non-magnetic in solid solution/annealed states.

• Thermal Capabilities: Exhibits an oxidation and heat scaling resistance profile up to an intermittent service ceiling of 870°C (1598°F).

Processing, Supply States & Dimensional Tolerances

The material is commonly supplied under specific fabrication standards such as ASTM A276 and ASTM A479, categorized by its mechanical processing path and surface topography:

• Cold-Drawn / Bright Bars: Precision-processed for high dimensional accuracy and structural rigidity. Typical diameter tolerances for cold-finished sections follow strict limits, ranging from ±0.001" for smaller fractions (under 5/16") to ±0.003" for larger sections up to 3.25". Common ISO tolerance grades include h8, h9, h11, and K9 to K12.

• Hot-Rolled / Forged Bars: Primarily targeted for heavy structural frameworks or rough machining blanks where tight initial tolerances are secondary. Rolling tolerances range loosely from +3/64" on smaller diameters up to +7/32" on massive hot-finished rounds over 12 inches.

• Surface Finishes Available: Peeled & Centerless Ground, Smooth Turned, Polished, or Raw Hot-Rolled Pickled (Black/Matte).

Standard Linear Weight Chart (Metric)

For calculating transport logistics, material estimation, or foundational structural loads, engineers utilize standard linear mass formulas based on the nominal outer diameter (OD).

Procurement Options

If you are sourcing specific sample quantities, precision pre-cut lengths, or bulk stock bars for immediate prototyping, several standard dimensional configurations are widely distributed online:

• For small-scale precision hobby engineering, instrumentation, or tight-tolerance pinning applications, the OnlineMetals 304 Stainless Steel Round Rod (0.125" x 48") offers an unpolished mill finish that is fully annealed to meet AMS 5639 and ASTM A276 standards.

• For standard mechanical component fabrication or prototyping infrastructure requiring balanced scaling lengths, the TMW Profiles Stainless Steel 304 Silver Round Rod (8mm x 1000mm) delivers a smooth, cold-drawn profile in a practical pre-cut metric size.

• For heavier mechanical shafts, industrial hardware blanks, or structural pins requiring a premium surface presentation, the MetaleMart Solid Stainless Steel Round Bar (82.55mm x 1000mm) delivers a massive, solid cross-section cut cleanly to a one-meter length.