Stainless Steel 304H Round Bar
➡️ SS 304H | UNS S30409 | EN 1.4948
➡️ ASTM, EN, JIS & International Standards
➡️ Supply Conditions
➡️ Multiple Diameters & Supply Lengths
➡️ Global Export & International Delivery
Country of Origin:
Europe, Japan, USA
Material Type:
Stainless Steel
UNS Number:
S30409
Wr. No.:
1.4948
MTC Available:
EN 10204 3.1
Product Description for Stainless Steel 304H Round Bar
Type 304H (UNS S30409) is the high-carbon version of Type 304, and bar is supplied mainly to ASTM A276 / A276M and ASTM A479 / A479M. Dimensions come from ASTM A484 / A484M, and ASME SA-479 covers pressure-equipment use.
What separates it from ordinary 304 is a carbon range rather than a carbon cap: 0.04-0.10%, with a floor as well as a ceiling. Carbon at that level raises creep and stress-rupture strength, which is why ASME approves the grade for pressure-retaining service above 525 C where 304 and 304L are not accepted. ASTM A479 also demands a coarse grain size of ASTM No. 7 or coarser, since fine-grained material creeps faster under the same load.
Bar is supplied solution annealed above roughly 1040 C and quenched fast. It can be hot-finished or cold-finished by drawing, peeling, turning or grinding, in diameters from about 6 mm to 300 mm, random or cut lengths. Grain size is verified to ASTM E112 and reported on the certificate alongside the chemistry.
Room-temperature corrosion resistance matches Type 304. The structure is fully austenitic, so annealed bar is non-magnetic and will not harden by heat treatment. The extra carbon does leave the grade more prone to sensitisation, so it is not the choice for wet intergranular corrosion service.
Machining, welding and general fabrication behave the same as standard Type 304, so nothing special is needed in the shop beyond keeping the material out of the sensitising range.
Most of it goes into high-temperature bolting, furnace and boiler internals, superheater supports, refinery and petrochemical process parts and heat-exchanger hardware.
Common Applications of Stainless Steel 304H Round Bar
➡️ Machined shafts, spindles, valve stems, pump sleeves and pins for food, beverage, dairy and pharmaceutical equipment, where the passive chromium oxide film resists both product acids and caustic clean-in-place chemicals.
➡️ Fasteners, studs, bolts, threaded rod and anchor components produced from bar stock, chosen for corrosion resistance combined with the ductility needed for cold heading and thread rolling.
➡️ Chemical, water treatment and general process plant parts such as agitator shafts, flange blanks, nozzles and support components handling water, steam and mildly corrosive media free of significant chlorides.
➡️ Architectural and structural hardware including handrail stanchions, balustrade fittings, tension rods and bollards, where a bright ground or polished bar finish provides both appearance and low maintenance.
International Equivalent Grade for SS 304H Round Bar
Standard
Country / Region
Grade
ASTM A276 / A276M
USA
Type 304H (UNS S30409)
ASTM A479 / A479M
USA
UNS S30409
ASME SA-479
USA
UNS S30409
EN 10088-3
Europe / EU
1.4948 (X6CrNi18-10)
BS EN 10088-3
United Kingdom
1.4948
GB/T 1220
China
07Cr19Ni10 (S30409)
ISO 15510
International
X6CrNi18-10
Technical Specification for Stainless Steel 304H Round Bar
Specification
Value
Unit
Material
Stainless steel
-
Grade
304H / UNS S30409 / 1.4948
-
Product Form
Round bar / rod
-
Standard
ASTM A276 / A276M, ASTM A479 / A479M, ASME SA-479
-
Diameter
6 - 300 (typical supply range)
mm
Length
3 - 6 (random), or cut to length
m
Manufacturing Process
Hot rolled or forged, solution annealed
-
Production Route
EAF + AOD refining, continuous cast or ingot
-
Surface Finish
Hot-rolled and pickled, cold-drawn, peeled, turned, centreless ground, polished
-
Heat Treatment / Delivery Condition
Solution annealed above 1040 C, water quenched
-
Grain Size Requirement
ASTM No. 7 or coarser, per ASTM A479
-
Tolerance Standard
ASTM A484 / A484M
-
Density
7.93 (typical)
g/cm3
Melting Range
1400 - 1455 (typical)
C
Thermal Conductivity at 100 C
16.2 (typical)
W/m.K
Coefficient of Thermal Expansion (20-100 C)
17.3 (typical)
um/m.C
Specific Heat (0-100 C)
500 (typical)
J/kg.K
Electrical Resistivity at 20 C
0.72 (typical)
uOhm.m
Modulus of Elasticity at 20 C
193 (typical)
GPa
Magnetic Properties
Non-magnetic in the solution-annealed condition
-
Maximum Service Temperature
870 (typical, intermittent to 925, oxidising atmosphere)
C
Testing / Inspection Standard
ASTM A370 for mechanical testing, ASTM E112 for grain size
-
Certification / Inspection Documents
EN 10204 3.1 or 3.2 mill test certificate
-
Technical Specifications
Get the key technical specifications for Stainless Steel 304H Round Bar
Buy to ASTM A276 / A276M or ASTM A479 / A479M under UNS S30409, with ASME SA-479 for pressure-retaining components. Tolerances on diameter and straightness, plus surface condition, come from ASTM A484 / A484M, and European practice specifies the grade as 1.4948 to EN 10088-3.
Two requirements have to be met, and both belong on the certificate. Carbon is controlled to 0.04-0.10%, a range rather than a ceiling, because a minimum carbon level is what produces the creep strength. Alongside that, ASTM A479 requires an austenitic grain size of ASTM No. 7 or coarser, measured to ASTM E112. Solution annealing above roughly 1040 C handles both at once, dissolving carbides and developing the grain size, and is followed by a fast quench.
The higher carbon leaves the grade more prone to sensitisation than 304L when it sits between roughly 450 C and 850 C, which cuts resistance to intergranular attack in wet service. That is an accepted trade in high-temperature work, where wet corrosion is not the mechanism doing the damage.
No heat treatment will strengthen the grade, so the only way up in strength is cold work. Bar comes hot-finished or cold-finished, and cold-finished material headed for hot service is normally re-annealed. Above about 525 C, design has to run on ASME allowable stress values rather than room-temperature tensile figures.
Chemical Composition for Stainless Steel 304H Round Bar
Element
Symbol
Min
Max
Unit
Carbon
C
0.04
0.10
%
Manganese
Mn
-
2.00
%
Silicon
Si
-
0.75
%
Phosphorus
P
-
0.045
%
Sulfur
S
-
0.030
%
Chromium
Cr
18.00
20.00
%
Nickel
Ni
8.00
11.00
%
Iron
Fe
Balance
-
%
Chemical Composition
View the chemical composition and applicable material limits for SS 304H Round Bar
Carbon defines this grade. Type 304 simply caps it at 0.08%. Type 304H specifies a controlled 0.04-0.10% range, and the floor matters as much as the ceiling. Carbon held in solid solution and as finely dispersed carbides gets in the way of dislocation movement at high temperature, and that is what raises creep and stress-rupture strength. Without the minimum, the material would not qualify for ASME pressure service above 525 C.
Chromium at 18.00-20.00% builds the passive oxide film behind corrosion resistance in atmospheric and mildly corrosive conditions, and supports oxidation resistance to roughly 870 C in continuous service.
Nickel at 8.00-11.00% keeps the structure austenitic across the whole temperature range, supplies ductility and toughness, and helps in reducing media.
Manganese and silicon deoxidise and add a little solid-solution strength. Nitrogen carries no limit for UNS S30409 in the ASTM composition tables and is not a deliberate addition here. Phosphorus and sulphur are residuals held down to protect hot workability, weldability and corrosion behaviour.
The higher carbon is the trade this grade makes. It buys creep performance and gives up resistance to chromium carbide precipitation in the 450-850 C band, which is why 304H is not specified where intergranular corrosion in aqueous service is the worry.
Mechanical Properties for Stainless Steel 304H Round Bar
Mechanical Property
Value
Unit
Tensile Strength
515
MPa (minimum)
Yield Strength 0.2% Proof
205
MPa (minimum)
Elongation in 50 mm
40
% (minimum, ASTM A276 Condition A)
Elongation in 50 mm, shapes 12.5 mm section and under
30
% (minimum, ASTM A276 footnote)
Reduction of Area
50
% (minimum, ASTM A276 Table 2)
Hardness
192
HBW (maximum, ASTM A479 annealed bar)
Hardness
90
HRB (maximum, ASTM A479 annealed bar)
Modulus of Elasticity
193
GPa (typical)
Mechanical Properties
Check the key mechanical properties and performance requirements of SS 304H Round Bar
Every figure shown is a minimum for solution-annealed bar, except hardness, which is a ceiling. ASTM A276 / A276M and ASTM A479 / A479M apply different hardness limits, so both appear separately: A276 allows up to 217 HBW or 95 HRB, while A479 tightens that to 192 HBW or 90 HRB on annealed bar. Testing is to ASTM A370 in the delivered condition.
At room temperature, 304H behaves exactly like Type 304, giving moderate strength with high ductility and toughness. The difference only shows up hot, where the controlled carbon and coarse grain deliver materially better creep and stress-rupture strength. For pressure design above roughly 525 C, ASME allowable stresses for S30409 are the valid basis. Room-temperature tensile numbers are not, and using them will produce an unsafe answer.
A fully austenitic structure means no ductile-to-brittle transition, so toughness holds all the way down to cryogenic temperatures.
No heat treatment will strengthen the grade. Cold drawing lifts tensile and proof strength while cutting elongation, and can leave the bar slightly magnetic, so material intended for high-temperature service is normally supplied re-annealed.
Dimension / Sizes for Stainless Steel 304H Round Bar
Dimension / Size
Value
Unit
Diameter
6 - 300
mm
Standard Length
3 - 6 (random / mill lengths)
m
Custom Length
Cut to length available on request
-
Diameter Tolerance
Per ASTM A484 / A484M, varies with size and finish class
-
Length Tolerance
Per ASTM A484 / A484M or as agreed at order
-
Straightness Tolerance
Per ASTM A484 / A484M or as agreed at order
-
End Condition
Square cut, chamfered, or as ordered
-
Surface Finish
Hot-rolled and pickled, cold-drawn, peeled, turned, centreless ground, polished
-
Available Size Range
6 - 300, larger diameters by forging on enquiry
mm
Cut-to-Length Availability
Available
-
Dimensional Standard
ASTM A484 / A484M
-
Dimensions & Sizes
Explore available diameters, lengths, and dimensional requirements for SS 304H Round Bar
Pricing for Stainless Steel 304H Round Bar
Round Bar Prices are generally quoted per kilograms or meters tonnes and can fluctuate with the global raw material and market prices. The final price will depend on a variety of factors, including the grade size, diameter, length, surface finish, the quantity and whether the bars are cut to length or in standard lengths.
For smaller quantities, we can also quote per metre or per piece basis once the required dimensions have been confirmed. Container-loads or orders that are larger in size are typically priced per tonne, based upon the specifications required and the supply conditions.
Please provide your desired dimensions, grades, length number, and end for a current quote including the lead time applicable and details for certification.
Pricing
Get current Stainless Steel 304H Round Bar pricing based on size, quantity, grade, finish, and delivery requirements.
Why Choose Us
Euro Steel Bars is an international distributor, stockist and exporter of stainless round steel bars that cover carbon, stainless alloy, special grades. We stock a variety of sizes and grades. We guarantee every order with mill test certificates as well as full quality-assurance documentation. Our name speaks to our roots: European-sourced materials that is backed by the certificates and rigor that buyers from Asia as well as the Gulf and Africa are looking for.
Each bar we deliver is accompanied by EN 10204 3.1 mill test certificates as well as complete documentation of quality, so what you receive corresponds to what’s written in the documents. We carry a selection of sizes and grades ready for transport, and cut length upon the request of customers, which results in quicker lead times, whether you’re ordering just a one-off spec or a complete project tonnage.
We operate an actual wholesale business that is that is supported with an internationally-operated supply chain therefore we are able to serve fabricators sourcing one grade the same way in the same way as an EPC contractor who is placing a large order. Our clients include manufacturers, fabricators EPC construction companies, engineers oil and gas projects as well as construction companies. we design our inventory as well as documentation to show what buyers need to bring projects forward.
Our customers trust us across Qatar, Oman, Bahrain, Kuwait, Jordan, Malaysia, Singapore, Thailand, Taiwan, Turkey, Italy and South Africa. If you’re looking to source an Gulf energy project, or a construction project within Southeast Asia, you get the same quality of certified material, the exact documentation, and the exact delivery procedure.
Frequently Asked Questions
What is Stainless Steel 304H Round Bar?
What is the difference between 304, 304L and 304H?
What standard does Stainless Steel 304H Round Bar comply with?
What are the equivalent grades of Stainless Steel 304H Round Bar?
What are the key mechanical properties of Stainless Steel 304H Round Bar?
Why does 304H require a coarse grain size?
Is Stainless Steel 304H suitable for corrosive aqueous service?
What sizes and lengths are available?
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