Carbon Steel A105 Round Bar
➡️ ASTM A105 | UNS K03504 | EN 1.0460
➡️ ASTM, EN, JIS & International Standards
➡️ Supply Conditions
➡️ Multiple Diameters & Supply Lengths
➡️ Global Export & International Delivery
Country of Origin:
Europe, Japan, USA
Material Type:
Carbon Steel
UNS Number:
K03504
Wr. No.:
1.0460
MTC Available:
EN 10204 3.1
Product Description for Carbon Steel A105 Round Bar
Carbon Steel A105 Round Bar is a solid cylindrical bar or forged round produced to ASTM A105 / A105M, the specification covering carbon steel forgings for piping applications. The corresponding ASME designation is SA105, and the material is assigned UNS K03504. Bar stock in this grade is used as forging feedstock and, where permitted by the applicable piping code, for machined components such as flanges, fittings, valve bodies and plugs.
The grade is a plain carbon-manganese steel with a maximum of 0.35% carbon and 0.60-1.05% manganese, together with limits on residual copper, nickel, chromium, molybdenum and vanadium. ASTM A105 imposes a carbon equivalent ceiling of 0.47 when carbon is at its maximum, which directly controls weldability and is one of the reasons the grade is so widely accepted for welded piping systems.
Mechanical requirements are mandatory: 485 MPa minimum tensile strength, 250 MPa minimum yield strength, 30% minimum elongation and 30% minimum reduction of area, with hardness not exceeding 187 HBW. Material may be supplied as-forged, or normalised, normalised and tempered, or quenched and tempered, depending on size and the purchaser’s requirements. Impact testing is not required by A105 unless specified.
Bar is available in diameters from about 20 mm to 600 mm in 3 to 6 m lengths, with larger forged rounds and billets produced to order. Typical uses include flanges of all types, weld neck and slip-on fittings, valve bodies and bonnets, unions, couplings, plugs, nipples and instrument fittings. Industries served include oil and gas, refining, petrochemical, power generation, water treatment and general process piping.
Common Applications of Carbon Steel A105 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 CS A105 Round Bar
Standard
Country / Region
Grade
ASTM A105 / A105M
USA
Grade A105 / A105N (UNS K03504)
ASME SA105 / SA105M
USA
SA105 / SA105N
EN 10222-2
Europe / EU
P250GH (1.0460) - nearest equivalent
BS EN 10222-2
United Kingdom
P250GH (1.0460) - nearest equivalent
JIS G3202
Japan
SFVC2A - nearest equivalent
KS D 3710
South Korea
SF490A - nearest equivalent
GB/T 12228
China
20 - nearest equivalent for general forgings
Technical Specification for Carbon Steel A105 Round Bar
Specification
Value
Unit
Material
Carbon steel
-
Grade
A105 / A105N / UNS K03504
-
Product Form
Round bar / forged round / forging stock
-
Standard
ASTM A105 / A105M and ASME SA105
-
Diameter
20 - 600 (available range)
mm
Length
3 - 6 (standard random or fixed)
m
Manufacturing Process
Forged, hot rolled, or hot rolled and machined
-
Production Route
EAF or BOF melting with ladle refining, ingot or continuous cast, forging or hot rolling, heat treatment
-
Surface Finish
As-forged and descaled, hot-rolled black, peeled, rough turned, machined
-
Heat Treatment / Delivery Condition
As-forged, annealed, normalised, normalised and tempered, or quenched and tempered as ordered
-
Normalising Temperature
870 - 925 then air cool (typical)
deg C
Carbon Equivalent (CEV)
0.47 max at 0.35 percent maximum carbon (mandatory per ASTM A105)
-
Carbon Equivalent (CEV)
0.48 max at 0.30 percent maximum carbon (mandatory per ASTM A105)
-
Tolerance Standard
ASTM A29 / A29M for bar dimensions
-
Density
7.85 (typical)
g/cm3
Melting Point
1500 (approximate)
deg C
Thermal Conductivity
51.9 at 100 deg C (typical)
W/m.K
Coefficient of Thermal Expansion
11.9 at 20 - 100 deg C (typical)
micro-m/m.K
Specific Heat
486 at 50 - 100 deg C (typical)
J/kg.K
Electrical Resistivity
0.170 (typical)
micro-ohm.m
Modulus of Elasticity
200 (typical)
GPa
Maximum Design Temperature
Governed by ASME B31.3 and ASME B16.5 pressure-temperature ratings
-
Magnetic Properties
Ferromagnetic
-
Applicable Testing Standard
ASTM A370, ASTM E8 / E8M, ASTM E10, ASTM E415, ASTM A788
-
Certification / Inspection Documents
EN 10204 Type 3.1 or 3.2 mill test certificate
-
Technical Specifications
Get the key technical specifications for Carbon Steel A105 Round Bar
Carbon Steel A105 Round Bar is governed by ASTM A105 / A105M, adopted by ASME as SA105. ASTM A788 / A788M applies as the general requirements standard for steel forgings, covering melting practice, discard, marking and reporting.
Unlike the AISI carbon grades, A105 imposes mandatory mechanical properties: a minimum tensile strength of 485 MPa, minimum yield of 250 MPa, 22% minimum elongation on a standard round or 4D specimen, and 30% minimum reduction of area, with a maximum hardness of 187 HBW and a 137-187 HBW band for flanges. Testing is required per production lot as defined by the standard.
The carbon equivalent requirement does a lot of work in this specification. A105 limits CE to 0.47 when carbon is at the 0.35% maximum, and permits 0.48 when maximum carbon is restricted to 0.30%, using the formula CE equals C plus Mn divided by 6 plus the sum of Cr, Mo and V divided by 5 plus the sum of Ni and Cu divided by 15. This ceiling is what makes the grade reliably weldable in field piping without excessive preheat.
Heat treatment is not a mandatory requirement of ASTM A105 for all products. It is required for ASME B16.5 flanges of Class 400, 900, 1500 and 2500, for flanges of special design where the design pressure at design temperature exceeds the Class 300 rating or where design conditions are unknown, and for forged fittings and valve parts over 4 in. NPS and above Class 300. Where applied, the permitted treatments are annealing, normalising, normalising and tempering, or quenching and tempering. Material designated A105N is supplied normalised.
Impact testing is not a requirement of A105. Where low-temperature service is intended, ASTM A350 grade LF2 should be specified instead, as it mandates Charpy testing.
Chemical Composition for Carbon Steel A105 Round Bar
Element
Symbol
Min
Max
Unit
Carbon
C
-
0.35
%
Manganese
Mn
0.60
1.05
%
Silicon
Si
0.10
0.35
%
Phosphorus
P
-
0.035
%
Sulfur
S
-
0.040
%
Copper
Cu
-
0.40
%
Nickel
Ni
-
0.40
%
Chromium
Cr
-
0.30
%
Molybdenum
Mo
-
0.12
%
Vanadium
V
-
0.08
%
Chromium plus Molybdenum combined
Cr + Mo
-
0.32
%
Total of Cu, Ni, Cr, Mo and V
-
-
1.00
%
Iron
Fe
Balance
Balance
%
Chemical Composition
View the chemical composition and applicable material limits for CS A105 Round Bar
Carbon is capped at 0.35% and manganese specified at 0.60-1.05%. Together these two elements provide essentially all of the strength in this grade. Carbon is deliberately restricted, because higher levels would raise the carbon equivalent above the permitted ceiling and compromise the field weldability on which piping construction depends. Manganese contributes solid solution strengthening, improves hardenability slightly and combines with sulphur to prevent hot shortness.
Silicon at 0.10-0.35% is specified as a range rather than a maximum, confirming that the steel must be fully killed. Killed steel has a cleaner, more uniform structure with better toughness and less risk of porosity in the forging.
Phosphorus and sulphur are limited to 0.035% and 0.040%. Both reduce toughness and ductility, and sulphur in particular reduces transverse properties in forged sections.
The residual element limits are a distinctive feature of A105. Copper, nickel, chromium, molybdenum and vanadium are each individually capped, the combined chromium plus molybdenum content must not exceed 0.32%, and the total of all five must not exceed 1.00%. These limits exist to prevent scrap-derived residuals from raising hardenability and carbon equivalent to a point where the heat-affected zone becomes crack-sensitive during welding.
The mandatory carbon equivalent ceiling of 0.47 ties all of these limits together into a single verifiable weldability criterion reported on the mill certificate.
Mechanical Properties for Carbon Steel A105 Round Bar
Mechanical Property
Value
Unit
Tensile Strength
485 (minimum)
MPa
Yield Strength
250 (minimum, 0.2% offset or 0.5% extension under load)
MPa
Elongation in 50 mm (standard round or 4D proportional specimen)
22 (minimum)
%
Elongation in 50 mm (strip specimen, wall 7.9 mm and over)
30 (basic minimum)
%
Reduction of Area (round specimens only)
30 (minimum)
%
Hardness
187 max
HBW
Hardness (flanges)
137 - 187 (specified range)
HBW
Impact / Charpy V-Notch
Not required by ASTM A105 unless invoked as a supplementary requirement
J
Modulus of Elasticity
200 (typical)
GPa
Mechanical Properties
Check the key mechanical properties and performance requirements of CS A105 Round Bar
ASTM A105 / A105M imposes mandatory mechanical requirements, which distinguishes it from the AISI carbon bar grades where properties are optional. Minimum tensile strength is 485 MPa and minimum yield strength is 250 MPa, determined by either the 0.2% offset method or the 0.5% extension-under-load method.
Elongation is specified in two ways and the distinction matters when reading a certificate. For a standard round 50 mm gauge length specimen, or a proportionally sized specimen with a 4D gauge length, the minimum is 22%. For strip specimens taken from walls of 7.9 mm and over, the basic minimum is 30%, reduced by 1.50 percentage points for each 0.8 mm the wall falls below 7.9 mm. Since bar and forged round stock are tested with round specimens, 22% is the figure that normally applies. Minimum reduction of area is 30% and applies to round specimens only.
Maximum hardness is 187 HBW. For flanges the standard specifies a two-sided band of 137 to 187 HBW, so material outside that range is rejected. The ceiling limits deliverable strength, protects machinability and weldability, and assists compliance where NACE MR0175 / ISO 15156 hardness limits apply.
Testing follows ASTM A370 and ASTM E8 / E8M with hardness to ASTM E10. Impact testing is not required by A105; for verified low-temperature toughness, ASTM A350 grade LF2 is the correct selection.
Dimension / Sizes for Carbon Steel A105 Round Bar
Dimension / Size
Value
Unit
Diameter (available range)
20 - 600
mm
Standard Length
3 - 6
m
Custom Length
Cut to length on request
-
Diameter Tolerance
Per ASTM A29 / A29M for hot-rolled bar or as agreed for forged rounds
-
Length Tolerance
Per ASTM A29 / A29M or as agreed
-
Straightness Tolerance
Per ASTM A29 / A29M or as agreed
-
End Condition
Square cut, saw cut, chamfered or as ordered
-
Surface Finish
As-forged and descaled, hot-rolled black, peeled, rough turned, machined
-
Cut-to-Length Availability
Available
-
Dimensional Standard
ASTM A29 / A29M for bar, ASME B16.5 and B16.11 for finished components
-
Dimensions & Sizes
Explore available diameters, lengths, and dimensional requirements for CS A105 Round Bar
Pricing for Carbon Steel A105 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 Carbon Steel A105 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 Carbon Steel A105 Round Bar?
What standard does Carbon Steel A105 Round Bar comply with?
What are the key mechanical properties of A105?
What is the carbon equivalent requirement for A105?
What is the difference between A105 and A105N?
Can A105 be used for low-temperature service?
What are the equivalent grades of ASTM A105?
What sizes are available in A105 round bar?
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