what is 904L stainless steel round bar?

what is 904L stainless steel round bar?

904L Stainless Steel Round Bar is a solid cylindrical metal product made from UNS N08904 (also known as 1.4539), an austenitic, super-austenitic stainless steel grade. It is specifically engineered for high corrosion resistance in aggressive, chloride-rich, and acidic environments, such as those found in chemical processing, offshore oil and gas, and pulp and paper industries.

 

What are the common specifications for 904L round bars?

904L round bar (UNS N08904, DIN 1.4539) is a high-alloy austenitic stainless steel, primarily specified under ASTM A276/A479 standards. Its key specifications include: a diameter range of 3 mm to 800 mm, a minimum tensile strength of 490 MPa, and a minimum yield strength of 220 MPa.

 

904L Stainless Steel Bar Supplier

GNEE supplies 904L super austenitic stainless steel round bars in accordance with ASTM A276. The material is solution annealed at 1100–1150°C followed by water quenching, ensuring excellent mechanical properties, including tensile strength ≥ 490 MPa, yield strength ≥ 215 MPa, and elongation ≥ 35%.

Our 904L stainless steel bars are available in hot rolled, cold rolled / cold drawn, and precision ground conditions. Surface finishes include black, bright, and ground finish (Ra ≤ 0.8 μm). We also provide value-added processing such as fixed-length cutting, chamfering, and threading.

 

All products are certified under ISO9001 and CE standards, with each batch supplied with MTC and third-party inspection reports from SGS/BV. Delivery time ranges from 7 to 30 days. Upon request, we can also provide intergranular corrosion testing (ASTM A262), pitting corrosion potential testing, and metallographic analysis reports, ensuring reliable long-term performance in highly corrosive environments.

 

SS 904L Round Bar Specification

Item	Specification
Standard	ASTM / ASME
Material Grade	SS 904L
Forms Available	Round, Square, Hex (A/F), Rectangle, Flat, Bush, Billet, Ingot, Forging, PSQ Bar, Wire Rod, Wire (Coil Form), Wire Mesh, etc.
Size Range (Diameter)	3.17 mm to 350 mm
Metric Size Range	M6 to M48
Imperial Size Range	1/4" to 2"
Pipe Size Equivalent	15NB to 150NB
Length	100 mm to 3000 mm & above (customized)
Manufacturing Process	Cold Drawn / Extruded
Tolerances	H8, H9, H10, H11, H12, H13, K9, K10, K11, K12 or as per customer requirement
Finishing Options	Black, Bright Polished, Rough Turned, No.4 Finish, Matt Finish, BA Finish, High Polished
Surface Condition	Hot Rolled Pickled / Sand Blasted / Cold Drawn / Bright / Polished / Hairline
Special Processing Condition	Cold Drawn Polished / Centreless Ground & Polished / Threading
Standard Compliance	NACE MR0175 / ISO 15156

 

What is the chemical composition of 904L round bar?

The chemical composition of 904L round bar (UNS N08904) characterizes it as a high-alloy "super-austenitic" stainless steel, distinguished by its high nickel content (23.00%–28.00%), high chromium content (19.00%–23.00%), and the addition of copper (1.00%–2.00%).

Grade	Ni	Mo	Cr	Cu	C	Mn	Si	P	S
904L	23 – 28	4 – 5	19 – 23	1 – 2	0.02 max	2.0 max	1.0 max	0.045 max	0.035 max

 

904L Stainless Steel Round Bars Mechanical & Physical Properties

Density	Melting Point	Tensile Strength	Yield Strength (0.2%Offset)	Elongation
8.05 g/cm3	1350 °C (2460 °F)	Psi – 71000 , MPa – 490	Psi – 32000 , MPa – 220	35 %

 

What welding filler metal should be used for 904L?

Use matching 904L filler (E385-16 or ER385) to ensure the weld zone has the same corrosion resistance as the base metal.

 

What are the industrial applications of 904L round bars?

Used for pump shafts, valves, fasteners, and stirrers in chemical processing, oil and gas refineries, pulp and paper production, and seawater cooling systems.

 

Is 904L stainless steel magnetic?

No. 904L stainless steel is a fully austenitic stainless steel; it is non-magnetic in all states and remains non-magnetic even after cold working or welding. Its structure remains stable due to its high nickel and molybdenum content, preventing it from becoming magnetic unlike other types of stainless steel.

 

What is the difference between 904L and 316L?

904L contains significantly more Nickel and Molybdenum and adds Copper. While 316L is resistant to general atmospheric corrosion, 904L is designed for severe acid environments (like sulfuric and phosphoric acid).

 

If you are searching for a supplier, GNEE can provide 904L round bars with h9/h11 tolerances, full PMI testing to verify the high Nickel/Copper content, and EN 10204 3.1 certification to ensure the material is genuine and compliant with international standards.

Product Forms:
904L Hot-Rolled Round Bars: Φ20–200 mm, Black / Pickled Surface (Gnee Stainless Steel).
904L Cold-Rolled / Cold-Drawn Round Bars: Φ3–50 mm, Bright Surface.
904L Precision-Ground Round Bars: Φ3–100 mm, Mirror / Matte Finish (Ra ≤ 0.8 μm).

 

904L Stainless Steel Bar Export Packaging

904L Small Diameter Precision Bars (3mm-20mm): We recommend using fiber tubes or thickened wooden crates to prevent bending and deformation of slender bars.

904L Large Diameter Black Bars (100mm+): Bulk packaging with end protection, secured with steel straps, is recommended to save on logistics costs.

CNC Machined Parts: For pre-cut short parts, we recommend using EPE (Expanded Polyethylene) padding for insulation and packing in wooden crates.

GNEE's Commitment:

We will adjust the packaging strength according to your shipping method (sea container, LCL, or air freight). We can also accommodate special marking requirements (such as neutral packaging or specific markings).