Stainless Steel 310S Round Bar
➡️ SS 310S | UNS S31008 | EN 1.4845
➡️ 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:
S31008
Wr. No.:
1.4845
MTC Available:
EN 10204 3.1
Product Description for Stainless Steel 310S Round Bar
Type 310S (UNS S31008) is a high-alloy austenitic heat-resisting stainless steel, generally ordered to ASTM A276 / A276M and ASTM A479 / A479M with dimensions to ASTM A484 / A484M. European practice specifies it as grade 1.4845 to EN 10095.
It carries nominally 25% chromium and 20% nickel, the highest combination among the common austenitic grades. That much chromium produces a dense, adherent oxide scale that resists spalling under thermal cycling, allowing continuous service to roughly 1150 C in oxidising atmospheres, while the high nickel keeps the austenitic structure stable at temperature and resists carburisation in furnace environments.
310S is the low-carbon version of Type 310, with carbon capped at 0.08% to improve weldability and cut carbide precipitation, at some cost in creep strength against 310H.
Supply is solution annealed at roughly 1040-1065 C then dropped into water, hot-finished or cold-finished by peeling, turning or grinding, in diameters from about 6 mm to 300 mm. The quench has to be quick, because the high chromium content leaves the grade open to sigma phase formation between roughly 650 C and 900 C, and carburisation resistance in furnace atmospheres depends on the nickel staying where it should.
Worth knowing that the intermittent service limit is lower than the continuous one, because repeated cycling cracks and spalls the protective scale.
Annealed bar is non-magnetic and will not take a hardening treatment. Sulphur-bearing atmospheres are the grade’s weak point, where the high nickel content becomes a liability.
Typical work includes furnace fixtures, muffles and retorts, radiant tubes, heat-treatment baskets, burner components and cryogenic hardware.
Common Applications of Stainless Steel 310S 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 310S Round Bar
Standard
Country / Region
Grade
ASTM A276 / A276M, ASTM A479 / A479M
USA
Type 310S (UNS S31008)
ASME SA-479
USA
UNS S31008
EN 10095
Europe / EU
1.4845 (X8CrNi25-21)
BS EN 10095
United Kingdom
1.4845
JIS G4303
Japan
SUS 310S
GB/T 1220
China
06Cr25Ni20 (S31008)
KS D 3706
South Korea
STS 310S
ISO 4955
International
X8CrNi25-21
Technical Specification for Stainless Steel 310S Round Bar
Specification
Value
Unit
Material
Stainless steel
-
Grade
310S / UNS S31008 / 1.4845
-
Product Form
Round bar / rod
-
Standard
ASTM A276 / A276M, ASTM A479 / A479M, EN 10095
-
Diameter
6 - 300
mm
Length
3 - 6, 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 1040-1065 C, water quenched
-
Tolerance Standard
ASTM A484 / A484M
-
Density
7.98
g/cm3
Melting Range
1400 - 1450
C
Thermal Conductivity at 100 C
14.2
W/m.K
Coefficient of Thermal Expansion (20-100 C)
15.9
um/m.C
Specific Heat (0-100 C)
500
J/kg.K
Electrical Resistivity at 20 C
0.78
uOhm.m
Modulus of Elasticity at 20 C
200
GPa
Magnetic Properties
Non-magnetic in the solution-annealed condition
-
Maximum Continuous Service Temperature
1150
C
Maximum Intermittent Service Temperature
1035
C
Testing / Inspection Standard
ASTM A370 for mechanical testing, ASTM A262 where specified
-
Certification / Inspection Documents
EN 10204 3.1 or 3.2 mill test certificate
-
Technical Specifications
Get the key technical specifications for Stainless Steel 310S Round Bar
Purchasing runs through ASTM A276 / A276M or ASTM A479 / A479M under UNS S31008, with ASME SA-479 for pressure-retaining components, or to EN 10095 as 1.4845 for heat-resisting work. Tolerances on diameter and straightness, plus surface condition, come from ASTM A484 / A484M.
Solution annealing runs 1040-1065 C followed by a fast quench. Speed matters here because the high chromium content leaves the grade open to sigma phase formation between roughly 650 C and 900 C, and sigma costs both ductility and corrosion resistance.
One feature of 310S catches people out: the maximum intermittent service temperature, around 1035 C, sits below the maximum continuous temperature of roughly 1150 C. Repeated heating and cooling cracks and spalls the protective oxide scale, exposing fresh metal each cycle, so anything involving frequent thermal cycling has to be rated at the lower figure.
Sulphur-bearing atmospheres are the main limitation. High nickel can form low-melting nickel sulphide eutectics, so ferritic grades such as 446 are the right answer in sulphidising service.
No heat treatment will strengthen the grade, and the only way up in strength is cold work. Where the material sees aqueous or condensing service rather than dry hot gas, carbide precipitation in the 450-850 C range can cut intergranular corrosion resistance, and ASTM A262 testing may be specified.
Chemical Composition for Stainless Steel 310S Round Bar
Element
Symbol
Min
Max
Unit
Carbon
C
-
0.08
%
Manganese
Mn
-
2.00
%
Silicon
Si
-
1.50
%
Phosphorus
P
-
0.045
%
Sulfur
S
-
0.030
%
Chromium
Cr
24.00
26.00
%
Nickel
Ni
19.00
22.00
%
Iron
Fe
Balance
-
%
Chemical Composition
View the chemical composition and applicable material limits for SS 310S Round Bar
Chromium at 24.00-26.00% is the highest among the common austenitic stainless steels and the main source of the heat resistance. At that level the alloy forms a thick, dense, strongly adherent chromium oxide scale that rebuilds quickly if damaged, which is what supports continuous service to roughly 1150 C in oxidising atmospheres.
Nickel at 19.00-22.00% is just as essential. It holds a stable fully austenitic structure to high temperature, heading off the brittle ferrite and phase changes a lower-nickel alloy would suffer, and it gives good resistance to carburisation in furnace and heat-treatment atmospheres. Nickel also supplies high ductility and toughness, including at cryogenic temperatures.
Carbon is capped at 0.08%, which is what distinguishes 310S from Type 310. Lower carbon improves weldability and cuts chromium carbide precipitation, and it costs some creep strength against the high-carbon variant 310H.
Silicon is allowed up to 1.50%, higher than in most austenitic grades, because it makes a useful secondary contribution to scaling resistance. Manganese deoxidises and stabilises austenite.
Phosphorus and sulphur are residuals restricted to protect hot workability and weldability. The alloy’s own high nickel content, meanwhile, is exactly what rules it out for service in sulphur-bearing hot gases.
Mechanical Properties for Stainless Steel 310S 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
200
GPa
Mechanical Properties
Check the key mechanical properties and performance requirements of SS 310S Round Bar
These describe solution-annealed bar, and all are minima bar one: hardness 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. Test pieces are taken from the bar as delivered and run to ASTM A370.
At room temperature the grade gives moderate strength with high ductility and excellent toughness, closely comparable to Type 304. A fully austenitic structure with high nickel means no ductile-to-brittle transition, so impact energy holds down to cryogenic temperatures, and that is why 310S also finds low-temperature work.
For hot service, room-temperature tensile data is not the criterion that governs. Strength falls steadily above about 600 C, and design has to run on creep and stress-rupture properties or ASME allowable stress values for S31008. Where creep strength is the priority, the high-carbon variant 310H is normally specified instead.
Long exposure between roughly 650 C and 900 C can precipitate sigma phase, which raises hardness while cutting room-temperature ductility and toughness sharply, so components that have seen long service in that band should be assessed before reuse.
Dimension / Sizes for Stainless Steel 310S Round Bar
Dimension / Size
Value
Unit
Diameter
6 - 300
mm
Standard Length
3 - 6
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 310S Round Bar
Pricing for Stainless Steel 310S 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 310S 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 310S Round Bar?
What is the difference between 310 and 310S?
What standard does Stainless Steel 310S Round Bar comply with?
What are the equivalent grades of Stainless Steel 310S Round Bar?
Why is the intermittent service temperature lower than the continuous one?
What are the key mechanical properties of Stainless Steel 310S Round Bar?
Can Stainless Steel 310S be used in sulphur-bearing atmospheres?
What sizes and lengths are available?
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