Stainless Steel 347 Round Bar
➡️ SS 347 | UNS S34700 | EN 1.4550
➡️ 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:
S34700
Wr. No.:
1.4550
MTC Available:
EN 10204 3.1
Product Description for Stainless Steel 347 Round Bar
In bar form, grade 347 (UNS S34700, W.Nr. 1.4550) is supplied to ASTM A276 / A276M. ASTM A484 / A484M sets the diameter, straightness and surface requirements. EN, JIS, GB/T and KS all carry an equivalent designation.
The grade is a niobium-stabilised 18/10 austenitic steel in which niobium is added at a minimum of ten times the carbon content. Niobium carbides form in preference to chromium carbides, protecting the steel against intergranular corrosion after welding and during prolonged exposure between 425 C and 815 C. Niobium stabilisation is more thermally stable than titanium in strongly oxidising conditions.
Bar leaves the mill in the solution annealed (Condition A, +AT) condition. Depending on the tolerance and surface a job needs, it can be hot finished, cold drawn, peeled, rough or smooth turned, centreless ground or polished. Diameters from 3 mm to 500 mm are usual, with larger sizes forged to order, in random 3 to 6 m lengths or cut to length. The grade cannot be hardened by heat treatment; higher strength is obtained only through cold working.
Work done in this grade includes welded high-temperature fittings, exhaust components and machined parts, mostly for the refining, aerospace, power generation and chemical processing industries. Documentation is usually an EN 10204 3.1 certificate listing the heat analysis, the mechanical test results and the condition supplied. In the annealed condition the steel is non-magnetic, though cold work can leave it slightly magnetic. Density is around 8.00 g/cm3 and the modulus of elasticity about 193 GPa. Third party inspection, positive material identification and non-destructive examination can be added at order stage.
Common Applications of Stainless Steel 347 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 347 Round Bar
Standard
Country / Region
Grade
ASTM A276 / A276M
USA
Type 347 (UNS S34700)
ASTM A479 / A479M
USA
Type 347 (UNS S34700)
ASME SA-479
USA
Type 347 (UNS S34700)
EN 10088-3
Europe / EU
1.4550 (X6CrNiNb18-10)
BS EN 10088-3
United Kingdom
1.4550 (X6CrNiNb18-10)
JIS G4303
Japan
SUS347
GB/T 1220
China
06Cr18Ni11Nb (S34778)
KS D 3706
South Korea
STS347
ISO 15510
International
X6CrNiNb18-10
Technical Specification for Stainless Steel 347 Round Bar
Specification
Value
Unit
Material
Stainless Steel
-
Grade
347 / UNS S34700 / W.Nr. 1.4550
-
Product Form
Round Bar / Rod
-
Standard
ASTM A276 / A276M and ASTM A479 / A479M
-
Diameter
3 - 500 (larger by forging on request)
mm
Length
3 - 6 (random mill length) or cut to length
m
Manufacturing Process
Hot rolled, forged or cold finished
-
Production Route
EAF + AOD / VOD refining, continuous cast or ingot, hot rolled or forged
-
Surface Finish
Hot-finished and pickled, cold-drawn, peeled, turned, ground or polished
-
Heat Treatment / Delivery Condition
Solution annealed (condition a, +at)
-
Tolerance Standard
ASTM A484 / A484M
-
Carbon Equivalent (CEV)
Not applicable (CEV applies to carbon and low-alloy steels)
-
Density
8.00 (nominal)
g/cm3
Melting Range
1400 - 1425 (typical)
C
Thermal Conductivity at 100 C
16.1 (typical)
W/m.K
Coefficient of Thermal Expansion (0-100 C)
16.6 (typical)
10-6/K
Specific Heat (0-100 C)
500 (typical)
J/kg.K
Electrical Resistivity at 20 C
0.73 (typical)
micro-ohm.m
Modulus of Elasticity at 20 C
193 (typical)
GPa
Magnetic Properties
Non-magnetic in the solution annealed condition, slight magnetism may develop after cold work
-
Applicable Testing / Inspection Standard
ASTM A370 (mechanical testing), ASTM E112 (grain size, where required), ASTM A262 (intergranular corrosion, when specified)
-
Certification / Inspection Documents
EN 10204 3.1 mill test certificate standard, 3.2 third-party, PMI, ultrasonic and dye-penetrant examination available on request
-
Technical Specifications
Get the key technical specifications for Stainless Steel 347 Round Bar
Buyers specify ASTM A276 / A276M and ASTM A479 / A479M for the material and ASTM A484 / A484M for dimensions and surface. In Europe the same steel is called 1.4550 (X6CrNiNb18-10). The ordered standard and condition should appear on the order and on the certificate.
Solution annealing is performed at approximately 980-1065 C followed by rapid cooling. A stabilising anneal near 900 C may be specified for the most demanding intergranular corrosion service.
Hot finished bar is rolled or forged, then heat treated and pickled. Cold finished bar is drawn, peeled, turned or ground after that. Diameter, out of round, straightness and length tolerances shift with size and finish class, so they are read from the dimensional standard or agreed case by case.
Niobium does not oxidise across the arc in the way titanium does, so 347 is often preferred over 321 where components are welded using processes with limited shielding or where filler metal transfer efficiency matters.
The physical properties quoted are typical mill values, not requirements of the standard. Testing is to ASTM A370, with results, analysis, condition and heat number on the certificate.
Chemical Composition for Stainless Steel 347 Round Bar
Element
Symbol
Min
Max
Unit
Carbon
C
-
0.08
%
Manganese
Mn
-
2.00
%
Silicon
Si
-
1.00
%
Phosphorus
P
-
0.045
%
Sulfur
S
-
0.030
%
Chromium
Cr
17.00
19.00
%
Nickel
Ni
9.00
12.00
%
Niobium (Columbium)
Nb (Cb)
10 x C
1.10
%
Chemical Composition
View the chemical composition and applicable material limits for SS 347 Round Bar
Niobium at a minimum of ten times carbon is the stabilising element. It forms NbC, which is stable to higher temperatures than TiC and gives better retention of intergranular corrosion resistance in highly oxidising service.
Chromium runs 17.00 to 19.00% here, and it is what makes the steel stainless: it builds the passive oxide film that resists attack. Nickel at 9.00 to 12.00% stabilises the structure and improves ductility and toughness. The standard also fixes niobium (columbium) 10 x C to 1.10%. Carbon is capped at 0.08%.
The manganese and silicon come from deoxidation and add slight strength. Phosphorus and sulphur are residual elements with low ceilings, because they cost hot workability, weldability and corrosion resistance.
ASTM, EN, JIS, GB/T and KS versions of the grade set slightly different limits. For general work the gap rarely matters; for severe corrosion or hot service it can, so check the heat analysis on the certificate against the standard ordered. Chemical analysis is carried out to ASTM A751. Where the composition table shows no limit for an element, the standard sets no requirement and the element need not be determined or reported.
Mechanical Properties for Stainless Steel 347 Round Bar
Mechanical Property
Value
Unit
Tensile Strength (Condition A, hot-finished)
515 (min)
MPa
Yield Strength 0.2% (Condition A, hot-finished)
205 (min)
MPa
Elongation in 50 mm (Condition A, hot-finished)
40 (min)
%
Reduction of Area (Condition A, hot-finished)
50 (min)
%
Tensile Strength (Condition A, cold-finished, up to 12.70 mm)
620 (min)
MPa
Yield Strength 0.2% (Condition A, cold-finished, up to 12.70 mm)
310 (min)
MPa
Tensile Strength (Condition A, cold-finished, over 12.70 mm)
515 (min)
MPa
Yield Strength 0.2% (Condition A, cold-finished, over 12.70 mm)
205 (min)
MPa
Elongation in 50 mm (Condition A, cold-finished)
30 (min)
%
Reduction of Area (Condition A, cold-finished)
40 (min)
%
Hardness (Brinell)
Not specified by ASTM A276 / A276M or ASTM A479 / A479M for this grade (typically 150 - 190 HBW as supplied)
HBW
Charpy V-Notch Impact at room temperature
60 - 120 (typical)
J
Modulus of Elasticity
193 (typical)
GPa
Mechanical Properties
Check the key mechanical properties and performance requirements of SS 347 Round Bar
Minimum values of 515 MPa tensile and 205 MPa yield apply in the annealed condition, with creep strength somewhat higher than unstabilised 304 at temperature.
The figures apply to solution annealed bar and are checked by tensile testing to ASTM A370 at room temperature. Cold finished bar work hardens while it is drawn or ground, so what arrives is often stronger than the minimum and less ductile than it. Toughness holds up to cryogenic temperatures, with no ductile to brittle transition.
For design, use the specified minima of the standard and condition ordered and take the real numbers from the mill certificate. Section size matters too, since diameter affects cooling rate during heat treatment and how much hot or cold work the bar has seen.
In selection terms, moderate strength combined with very high ductility and toughness favours components that must be formed, welded or extensively machined rather than carry high stress in thin sections. Where greater strength is needed at similar corrosion resistance, cold-worked bar, a duplex grade or a precipitation-hardening grade is normally evaluated instead. Machinability is moderate, and work hardening during cutting should be managed with sharp tooling, positive feed and rigid setups.
Dimension / Sizes for Stainless Steel 347 Round Bar
Dimension / Size
Value
Unit
Diameter (standard supply range)
3 - 500 (larger by forging on request)
mm
Standard Length
3 - 6 (random mill length)
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 on the order
-
Straightness Tolerance
Per ASTM A484 / A484M or as agreed on the order
-
End Condition
Square cut, saw cut, chamfered or as ordered
-
Surface Finish
Hot-finished and pickled, cold-drawn, peeled, turned, ground or polished
-
Available Size Range (cold-finished bar)
3 - 100 (typical commercial capability)
mm
Available Size Range (hot-finished and forged bar)
16 - 500 (typical commercial capability)
mm
Cut-to-Length Availability
Available, tolerance to be agreed at order stage
-
Applicable Dimensional Standard
ASTM A484 / A484M
-
Dimensions & Sizes
Explore available diameters, lengths, and dimensional requirements for SS 347 Round Bar
Pricing for Stainless Steel 347 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 347 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 347 Round Bar?
What standard does Stainless Steel 347 Round Bar comply with?
What are the equivalent grades of Stainless Steel 347 Round Bar?
What sizes and lengths are available in Stainless Steel 347 Round Bar?
What are the key mechanical properties of Stainless Steel 347 Round Bar?
What is the typical chemical composition of Stainless Steel 347 Round Bar?
Can Stainless Steel 347 Round Bar be supplied cut to length or with a specific surface finish?
What is the difference between 321 and 347 round bar?
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