Alloy Steel EN25 Round Bar
➡️ EN25 | 826M31 | UNS G31250 | EN 1.6743 | 30Cr2Ni2Mo
➡️ ASTM, EN, JIS & International Standards
➡️ Supply Conditions
➡️ Multiple Diameters & Supply Lengths
➡️ Global Export & International Delivery
Country of Origin:
Europe, Japan, USA
Material Type:
Alloy Steel
UNS Number:
G31250
Wr. No.:
1.6743
MTC Available:
EN 10204 3.1
Product Description for Alloy Steel EN25 Round Bar
Alloy Steel EN25 Round Bar is a high-nickel chromium-molybdenum steel known in the British system as EN25 and in BS 970 as 826M31. It contains about 0.27–0.35% carbon, 2.30–2.80% nickel, 0.50–0.80% chromium and 0.45–0.65% molybdenum.
The high nickel and molybdenum content gives very good hardenability and excellent toughness, including impact toughness at low temperature. EN25 is supplied hardened and tempered to BS 970 tensile conditions, commonly T, U or V.
Compared with EN24, EN25 has lower carbon and more nickel and molybdenum. This gives higher toughness at similar strength levels and good resistance to temper embrittlement.
EN25 is made as hot rolled or forged bar, peeled or turned, annealed or hardened and tempered.
Common applications include heavy-duty shafts, gears, crankshafts, connecting rods, aircraft and automotive parts, and highly stressed components that must resist shock loads. No direct EN or ASTM equivalent has been identified, so buyers usually order to BS 970 826M31 or to an agreed specification. EN25 is a traditional British 2.5% nickel steel. It is less common today than EN24, but it is still specified on older drawings and for parts where toughness at moderate strength matters most, such as heavy gears, mining parts and defence components. Because there is no current EN grade, EN25 is usually bought from specialist mills or forges and made to order rather than taken from general stock. Large bars are usually forged and ultrasonically tested. Because EN25 is made to order, buyers should allow for longer lead times and minimum melt or forging quantities, and agree test positions early.
Common Applications of Alloy Steel EN25 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 EN25 Round Bar
Standard
Country / Region
Grade
UNS
USA
UNS G31250
AISI / SAE
USA
AISI 4340 / SAE 4340
EN 10083-3
Europe
EN 1.6743
BS
UK
BS 970 EN25 / 826M31
JIS
Japan
JIS SNCM447
GB
China
30Cr2Ni2Mo
KS
South Korea
KS D3867 SNCM447
IS
India
31Ni10Cr3Mo6
Technical Specification for Alloy Steel EN25 Round Bar
Specification
Value
Unit
Material
Alloy steel
-
Grade
EN25 / 826M31
-
Standard
BS 970-3 (826M31)
-
Product Form
Round bar (hot rolled, forged or bright)
-
Diameter (supply range)
10–500
mm
Length (random)
3–6
m
Manufacturing Process
Hot rolled or forged, optional peeling, turning, cold drawing or grinding
-
Production Route
EAF or BOF + ladle refining + vacuum degassing
-
Surface Finish
Black, shot blasted, peeled, turned, cold drawn or ground
-
Heat Treatment / Delivery Condition
Annealed or hardened and tempered (conditions T, U, V)
-
Tolerance Standard
EN 10060 (hot rolled), EN 10278 (bright, h9-h11), or as agreed
-
Carbon Equivalent CEV (IIW, calculated from mid-range analysis)
≈ 0.82
-
Density
7.85
g/cm³
Thermal Conductivity at 20°C
42
W/m·K
Coefficient of Thermal Expansion 20–100°C
11.5
µm/m·K
Specific Heat at 20°C
460
J/kg·K
Modulus of Elasticity at 20°C
210
GPa
Magnetic Properties
Ferromagnetic
-
Testing / Inspection
Chemical analysis, hardness, tensile and impact where specified, UT (EN 10308 / SEP 1921 / ASTM A388), grain size, Jominy on request
-
Certification
EN 10204 3.1 mill test certificate (3.2 on request)
-
Technical Specifications
Get the key technical specifications for Alloy Steel EN25 Round Bar
EN25 Round Bar is ordered to BS 970 as 826M31 in a named condition. As BS 970 is withdrawn and there is no direct EN grade, orders often quote BS 970 limits as an agreed specification.
Hardening is normally done from about 820–850°C with oil quenching, followed by tempering at about 550–660°C to reach the required condition.
The high hardenability allows the conditions to be met in larger ruling sections than many other steels.
EN25 is hard to weld because of its high carbon equivalent and needs full preheat and post-weld heat treatment. Ultrasonic testing and third-party witnessing of EN25 bars can be arranged.
When a drawing names EN25, check whether the designer requires the BS 970 826M31 chemistry exactly or will accept a modern equivalent. The closest EN grades, such as 30CrNiMo8 (1.6580) to EN 10083-3, have different chromium and nickel balances and are not direct equivalents. If exact 826M31 chemistry is required, order to BS 970 as an agreed specification and ask for the full heat analysis. For large forgings, specify ultrasonic testing, test positions and impact tests at the lowest service temperature.
Hardness checks along each bar help confirm uniform heat treatment.
Chemical Composition for Alloy Steel EN25 Round Bar
Element
Symbol
Min
Max
Unit
Carbon
C
0.27
0.35
%
Silicon
Si
0.10
0.35
%
Manganese
Mn
0.45
0.70
%
Phosphorus
P
-
0.035
%
Sulfur
S
-
0.040
%
Chromium
Cr
0.50
0.80
%
Molybdenum
Mo
0.45
0.65
%
Nickel
Ni
2.30
2.80
%
Chemical Composition
View the chemical composition and applicable material limits for EN25 Round Bar
The table shows BS 970 limits for 826M31 (EN25).
Carbon at 0.27–0.35% gives high strength after hardening with good toughness. Nickel at 2.30–2.80% is the main toughness element and also adds hardenability.
Molybdenum at 0.45–0.65% strongly increases hardenability and resistance to temper embrittlement. Chromium at 0.50–0.80% adds hardenability and strength.
Manganese and silicon in EN25 mainly deoxidise the melt. Nickel at 2.30–2.80% is higher than in EN24, and chromium at 0.50–0.80% is lower. This balance gives EN25 excellent toughness, especially at low temperature, because nickel lowers the impact transition temperature. Molybdenum at 0.45–0.65% is also higher than in EN24, which strongly raises hardenability and makes the steel very resistant to temper embrittlement, even when large parts cool slowly after tempering. Carbon at 0.27–0.35% is lower than in EN24 and EN26, which keeps the steel tougher at the same strength. Its manganese of 0.45–0.70% adds a little hardenability.
Phosphorus and sulfur should be kept low, and the certificate should show the full heat analysis, including residual copper and tin, because these can affect temper embrittlement over time. Low sulfur also improves transverse toughness.
Mechanical Properties for Alloy Steel EN25 Round Bar
Mechanical Property
Value
Unit
Tensile Strength (condition T)
850–1000
MPa
Hardness (condition T)
248–302
HB
Tensile Strength (condition U)
925–1075
MPa
Hardness (condition U)
269–331
HB
Tensile Strength (condition V)
1000–1150
MPa
Hardness (condition V)
293–352
HB
Mechanical Properties
Check the key mechanical properties and performance requirements of EN25 Round Bar
The values shown are BS 970 tensile and hardness ranges for EN25 in conditions T, U and V. Each EN25 condition has a ruling section limit, and yield, elongation and impact values depend on condition and size.
EN25 gives very good impact toughness at these strength levels, which makes it suitable for shock-loaded parts.
The EN25 certificate should show the condition letter and the test position. EN25 is usually ordered in condition T, U or V. Because of its very high hardenability, these conditions can be reached in large sections that would not be possible with EN19 or with lower-alloy steels. The main advantage is not higher strength but better impact toughness at the same strength level, which reduces the risk of brittle fracture in shock-loaded parts. For design, ask the mill for yield strength, elongation and impact results at the actual ruling section, and consider low-temperature impact tests for parts used in cold climates or cold storage.
Condition T gives 850–1000 MPa and about 248–302 HB, U gives 925–1075 MPa and V gives 1000–1150 MPa. For shock-loaded parts, many designers stay at T or U to keep toughness high.
Dimension / Sizes for Alloy Steel EN25 Round Bar
Dimension / Size
Value
Unit
Available Diameter Range (supply capability)
10–500 (forged sizes on request)
mm
Standard Length (random)
3–6
m
Custom / Cut-to-Length
Available on request
-
Diameter Tolerance
EN 10060 (hot rolled), EN 10278 (bright, h9-h11), or as agreed
-
Length Tolerance
Per ordered standard or as agreed (commonly +50 / -0 mm for cut lengths)
-
Straightness Tolerance
Per EN 10060 / EN 10278 or as agreed
-
End Condition
Saw cut square, chamfered or as ordered
-
Surface Finish
Black (as rolled or forged), shot blasted, peeled, rough turned, cold drawn, centreless ground
-
Dimensions & Sizes
Explore available diameters, lengths, and dimensional requirements for EN25 Round Bar
Pricing for Alloy Steel EN25 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 Alloy Steel EN25 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
Should I choose EN25 or EN24?
What is the difference between EN25 and EN24?
Does EN25 have a modern EN equivalent?
Why is EN25 used for shock-loaded parts?
How is EN25 heat treated, welded and machined?
What are the limits of EN25?
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