Stainless Steel 321H Round Bar
➡️ SS 321H | UNS S32109 | EN 1.4878
➡️ 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:
S32109
Wr. No.:
1.4878
MTC Available:
EN 10204 3.1
Product Description for Stainless Steel 321H Round Bar
Type 321H (UNS S32109) is the high-carbon version of titanium-stabilised Type 321, usually supplied against ASTM A276 / A276M and ASTM A479 / A479M with dimensions to ASTM A484 / A484M. ASME SA-479 covers pressure-equipment use.
Carbon is controlled to a 0.04-0.10% range rather than simply capped, and titanium is specified at a minimum of four times the combined carbon and nitrogen content rather than the five times used in 321. The deliberate carbon raises creep and stress-rupture strength, so the grade is approved for pressure-retaining service at higher temperatures than standard 321, while titanium stabilisation still guards against intergranular corrosion in the sensitisation range.
Bar is supplied solution annealed above roughly 1050 C and cooled rapidly in water, often with a stabilising anneal at 850-900 C afterwards. It can be hot-finished or cold-finished by drawing, peeling, turning or grinding, in diameters from about 6 mm to 300 mm.
Titanium is lost across the welding arc, so stabilised or over-alloyed filler metals are used, and a post-weld stabilising anneal is sometimes specified for demanding refinery work.
ASTM A479 also requires a grain size of ASTM No. 7 or coarser, verified to ASTM E112, since coarse-grained material creeps more slowly. Above roughly 525 C, design runs on ASME allowable stress values rather than room-temperature tensile figures.
The structure is fully austenitic, so annealed bar is non-magnetic and gains nothing from a hardening treatment. Continuous oxidising service to roughly 870 C is normal.
Most of it goes into superheater and reheater supports, high-temperature bolting, refinery heater components, furnace hangers, expansion joint hardware and pressure-vessel internals working in the creep range.
Common Applications of Stainless Steel 321H 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 321H Round Bar
Standard
Country / Region
Grade
ASTM A276 / A276M
USA
Type 321H (UNS S32109)
ASTM A479 / A479M
USA
UNS S32109
ASME SA-479
USA
UNS S32109
EN 10095 / DIN 17440
Europe / EU
1.4878 (X8CrNiTi18-10)
BS EN 10095
United Kingdom
1.4878
GB/T 1220
China
07Cr19Ni11Ti (S32169)
ISO 4955
International
X8CrNiTi18-10
Technical Specification for Stainless Steel 321H Round Bar
Specification
Value
Unit
Material
Stainless steel
-
Grade
321H / UNS S32109 / 1.4878
-
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, optionally stabilise 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 1050 C water quenched, stabilise anneal 850-900 C optional
-
Grain Size Requirement
ASTM No. 7 or coarser, per ASTM A479
-
Tolerance Standard
ASTM A484 / A484M
-
Density
7.90 (typical)
g/cm3
Melting Range
1400 - 1425 (typical)
C
Thermal Conductivity at 100 C
16.1 (typical)
W/m.K
Coefficient of Thermal Expansion (20-100 C)
16.6 (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, continuous, 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 321H Round Bar
Supply runs to ASTM A276 / A276M or ASTM A479 / A479M under UNS S32109, with ASME SA-479 for pressure-retaining components. Permissible variations on diameter, straightness and surface come from ASTM A484 / A484M.
Three things separate 321H from standard 321, and all three should be verified on the certificate. Carbon is controlled to a 0.04-0.10% range rather than a ceiling, because a minimum carbon level is what produces the creep strength. Titanium is set at a minimum of four times the combined carbon and nitrogen rather than five times, a ratio matched to the higher carbon while still guaranteeing stabilisation. ASTM A479 also requires an austenitic grain size of ASTM No. 7 or coarser, measured to ASTM E112, since coarse-grained material creeps more slowly.
Solution annealing above roughly 1050 C followed by a fast quench dissolves carbides and develops the grain size in one operation. A stabilising anneal at 850-900 C often follows, tying up carbon as titanium carbide before service and cutting the risk of knife-line attack beside welds.
Heat treating does nothing for the grade. For pressure design above roughly 525 C, ASME allowable stress values for S32109 are the valid basis rather than room-temperature tensile data. Cold-finished bar headed for hot service is normally supplied re-annealed.
Chemical Composition for Stainless Steel 321H 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
17.00
19.00
%
Nickel
Ni
9.00
12.00
%
Titanium
Ti
4 x (C+N)
0.70
%
Nitrogen
N
-
0.10
%
Iron
Fe
Balance
-
%
Chemical Composition
View the chemical composition and applicable material limits for SS 321H Round Bar
Carbon runs 0.04-0.10%, a controlled range rather than a cap, and the floor is as significant as the ceiling. Carbon in solid solution and as a fine carbide dispersion resists dislocation movement at high temperature, and that is where the improved creep and stress-rupture strength over standard 321 comes from. It is also what qualifies the grade for higher-temperature pressure service.
Titanium at a minimum of four times the combined carbon and nitrogen, capped at 0.70%, provides the stabilisation. It combines with carbon in preference to chromium, forming titanium carbide and leaving chromium dissolved in the matrix to maintain the passive film. The multiplier is four here rather than the five used in 321, matched to this grade’s higher carbon range.
Chromium at 17.00-19.00% supplies general corrosion resistance and supports oxidation resistance in continuous service to roughly 870 C. Nickel at 9.00-12.00% holds the austenitic structure and provides ductility and toughness across the full temperature range.
Nitrogen up to 0.10% contributes modest solid-solution strengthening. Manganese and silicon deoxidise, and phosphorus and sulphur are residuals restricted to protect hot workability, weldability and corrosion behaviour. Since titanium oxidises readily, some is lost across the welding arc, so stabilised or over-alloyed fillers are used for welded construction.
Mechanical Properties for Stainless Steel 321H 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 321H Round Bar
Solution-annealed bar is what the table describes. Minima throughout, with hardness the one ceiling. ASTM A276 / A276M and ASTM A479 / A479M apply different hardness limits, so both are shown: A276 allows up to 217 HBW or 95 HRB, while A479 tightens that to 192 HBW or 90 HRB on annealed bar. Testing follows ASTM A370 in the delivered condition.
Room-temperature properties are effectively identical to standard 321: moderate strength, high ductility, excellent toughness. The distinction lies entirely in hot behaviour, where the controlled carbon range and coarse grain give higher creep and stress-rupture strength. That is what earns ASME approval for pressure-retaining service at temperatures where 321 and 304L are not acceptable.
Above roughly 525 C, use ASME allowable stress values for S32109. Room-temperature tensile figures are not a valid design basis for creep-controlled service.
A fully austenitic structure means no ductile-to-brittle transition, so impact toughness holds at cryogenic temperatures, though no mandatory Charpy requirement applies to bar. Heat treating does nothing for the grade, and cold work raises strength only at the expense of ductility, with slight magnetism possible.
Dimension / Sizes for Stainless Steel 321H 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 321H Round Bar
Pricing for Stainless Steel 321H 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
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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 321H Round Bar?
What is the difference between 321 and 321H?
What standard does Stainless Steel 321H Round Bar comply with?
What are the equivalent grades of Stainless Steel 321H Round Bar?
What are the key mechanical properties of Stainless Steel 321H Round Bar?
Why is a stabilising anneal sometimes applied to 321H?
Where is Stainless Steel 321H Round Bar commonly used?
What sizes and lengths are available?
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