Alloy Steel 34CrNiMo6 Round Bar
➡️ UNS G43400 | EN 1.6582 | AISI 4340 | ASTM A29
➡️ 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:
G43400
Wr. No.:
1.6582
MTC Available:
EN 10204 3.1
Product Description for Alloy Steel 34CrNiMo6 Round Bar
Alloy Steel 34CrNiMo6 Round Bar is a nickel-chromium-molybdenum quenched and tempered steel to EN 10083-3, with material number 1.6582. It contains about 0.30–0.38% carbon, 1.30–1.70% chromium, 1.30–1.70% nickel and 0.15–0.30% molybdenum.
This is one of the highest-strength standard steels for quenching and tempering. The combination of nickel, chromium and molybdenum gives very high hardenability. Large sections can be hardened through, and they keep high strength and good toughness after tempering.
After quenching and tempering, the steel offers high tensile and yield strength, good fatigue strength and good impact toughness, even at low temperatures. Molybdenum also reduces the risk of temper embrittlement.
Bars are supplied hot rolled or forged, in the soft annealed (+A), treated for shearing (+S) or quenched and tempered (+QT) condition. The UK counterpart is BS 970 817M40 (EN24), and the nearest American grade is AISI 4340.
Common applications include heavy-duty shafts, crankshafts, axles, gears, connecting rods, high-strength bolts and studs, hydraulic parts, and parts for aircraft, power generation, oil and gas, and heavy machinery. It is chosen where strength and toughness must both be high in large sections. EN 10083-3 gives quenched and tempered properties for 34CrNiMo6 up to a ruling section of 250 mm, and still guarantees 600 MPa minimum yield strength in the 160–250 mm band. Few Cr-Mo steels hold strength that deep into a bar, which is why forges choose it for the biggest shafts in a machine. Its nickel also keeps impact toughness good in cold climates, which suits mining, marine and wind equipment.
Common Applications of Alloy Steel 34CrNiMo6 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 34CrNiMo6 Round Bar
Standard
Country / Region
Grade
UNS
USA
UNS G43400
ASTM A29 / AISI / SAE
USA
4340 / 4337
EN 10083-3
Europe
EN 1.6582 (34CrNiMo6)
BS 970
United Kingdom
EN24 / 817M40
JIS G4053
Japan
SNCM447 / SNCM439
GB/T 3077
China
34CrNi3Mo / 34CrNiMo / 40CrNiMoA
KS
South Korea
KS SNCM447 / KS SNCM439
AFNOR
France
35NCD6
UNI
Italy
35CrNiMo6 / 35NiCrMo6KB
GOST
Russia
38KH2N2MA / 40KHN2MA
ISO 683-2
International
34CrNiMo6
Technical Specification for Alloy Steel 34CrNiMo6 Round Bar
Specification
Value
Unit
Material
Alloy steel
-
Grade
34CrNiMo6 / 1.6582
-
Standard
EN 10083-3 (forgings EN 10250-3)
-
Product Form
Round bar (hot rolled, forged or bright)
-
Diameter (supply range)
20–800 (forged)
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
+A, +S or +QT as ordered
-
Tolerance Standard
EN 10060 (hot rolled), EN 10278 (bright, h9-h11), ASTM A29 / A484 style tables for US orders
-
Carbon Equivalent CEV (IIW, calculated from mid-range analysis)
≈ 0.89
-
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 34CrNiMo6 Round Bar
Alloy Steel 34CrNiMo6 Round Bar is ordered to EN 10083-3, which covers alloy steels for quenching and tempering. Very large 34CrNiMo6 shafts are often ordered as open-die forgings to EN 10250-3. The delivery condition must be stated, usually +A for machining before heat treatment, or +QT for ready-to-use strength.
Hardening is usually done from about 830–860°C with oil or water quenching, followed by tempering at about 540–660°C. The tempering temperature sets the final strength and toughness.
Mechanical properties in EN 10083-3 depend on the diameter of the bar, so the ruling section should be stated. Ultrasonic testing is common for large forged bars.
At about 0.89, the carbon equivalent of 34CrNiMo6 is the highest of the common EN 10083-3 grades. Welding needs preheat, controlled interpass temperature and post-weld heat treatment, and is usually avoided on quenched and tempered parts. The physical values for 34CrNiMo6 are reference data for Ni-Cr-Mo steel.
A useful point for buyers is that 34CrNiMo6 keeps strength deep into the section. EN 10083-3 still lists minimum yield strength of 600 MPa for the 160–250 mm range, where 42CrMo4 drops to 500 MPa. When ordering +QT bar, state the ruling section and the strength class, and ask the mill to report where the test piece was taken, usually at one quarter of the diameter for large bars. For critical shafts, add ultrasonic testing to EN 10308 or EN 10228-3 with a stated quality class.
Chemical Composition for Alloy Steel 34CrNiMo6 Round Bar
Element
Symbol
Min
Max
Unit
Carbon
C
0.30
0.38
%
Silicon
Si
-
0.40
%
Manganese
Mn
0.50
0.80
%
Phosphorus
P
-
0.025
%
Sulfur
S
-
0.035
%
Chromium
Cr
1.30
1.70
%
Molybdenum
Mo
0.15
0.30
%
Nickel
Ni
1.30
1.70
%
Chemical Composition
View the chemical composition and applicable material limits for 34CrNiMo6 Round Bar
The table shows the EN 10083-3 heat analysis limits for 34CrNiMo6.
Carbon at 0.30–0.38% gives the potential for high strength after hardening. Chromium at 1.30–1.70% and nickel at 1.30–1.70% work together to give very high hardenability, so large sections harden more evenly through the section.
Nickel also improves toughness, especially at low temperature. Molybdenum at 0.15–0.30% adds hardenability, improves resistance to softening during tempering and reduces temper embrittlement.
Manganese helps hardenability and deoxidation. Phosphorus and sulfur are impurities kept low to protect toughness and fatigue strength. A controlled sulfur version can be ordered for machinability. The balanced nickel and chromium content, both at 1.30–1.70%, is what makes 34CrNiMo6 different from plain Cr-Mo steels. Nickel lowers the critical cooling rate, so the centre of a thick bar still forms a tough tempered martensite after oil quenching. Nickel also lowers the ductile-to-brittle transition temperature, which helps shafts that must work in cold climates. Manganese is held at 0.50–0.80%, a little lower than in 42CrMo4, to limit temper embrittlement, which is a known risk in Ni-Cr steels. Silicon is limited to 0.40% maximum. For shafts that will be heavily machined, the supplier can offer a controlled sulfur range, but this may reduce transverse toughness and should be agreed with the designer.
Mechanical Properties for Alloy Steel 34CrNiMo6 Round Bar
Mechanical Property
Value
Unit
Yield Strength Re (+QT, d ≤ 16 mm)
≥ 1000
MPa
Tensile Strength Rm (+QT, d ≤ 16 mm)
1200–1400
MPa
Yield Strength Re (+QT, 16 < d ≤ 40 mm)
≥ 900
MPa
Tensile Strength Rm (+QT, 16 < d ≤ 40 mm)
1100–1300
MPa
Yield Strength Re (+QT, 40 < d ≤ 100 mm)
≥ 800
MPa
Tensile Strength Rm (+QT, 40 < d ≤ 100 mm)
1000–1200
MPa
Yield Strength Re (+QT, 100 < d ≤ 160 mm)
≥ 700
MPa
Tensile Strength Rm (+QT, 100 < d ≤ 160 mm)
900–1100
MPa
Yield Strength Re (+QT, 160 < d ≤ 250 mm)
≥ 600
MPa
Tensile Strength Rm (+QT, 160 < d ≤ 250 mm)
800–950
MPa
Elongation A (+QT, 16 < d ≤ 40 mm)
≥ 10
%
Impact Energy KV at +20°C (+QT, d > 16 mm)
≥ 45
J
Hardness (+A, soft annealed)
≤ 248
HB
Mechanical Properties
Check the key mechanical properties and performance requirements of 34CrNiMo6 Round Bar
The values shown are EN 10083-3 minimum and range requirements for 34CrNiMo6 in the quenched and tempered (+QT) condition. They depend on bar diameter because larger sections cool more slowly during quenching. Elongation and reduction of area also change with size, rising as strength falls.
The steel reaches very high strength in small and medium sections while keeping good impact toughness. Minimum impact energy of 45 J at room temperature applies for diameters above 16 mm.
In the soft annealed condition, hardness is limited to 248 HB for machining. Design with the 34CrNiMo6 band that matches the finished part size, and check it on the certificate. The strength bands in EN 10083-3 fall step by step with section size: for example, minimum yield strength is 1000 MPa up to 16 mm, 900 MPa for 16–40 mm, 800 MPa for 40–100 mm, 700 MPa for 100–160 mm and 600 MPa for 160–250 mm. Tensile strength is given as a range, not only a minimum, so over-strength bar can also be rejected. Engineers should choose the strength class that matches the part size, rather than the highest value in the table. At very high strength levels, notch sensitivity and hydrogen embrittlement rise, so many designers limit hardness for bolts and plated parts.
Dimension / Sizes for Alloy Steel 34CrNiMo6 Round Bar
Dimension / Size
Value
Unit
Available Diameter Range (supply capability)
20–800 (forged, larger on request)
mm
Standard Length (random)
3–6
m
Custom / Cut-to-Length
Available on request
-
Diameter Tolerance
Hot rolled: EN 10060 or ASTM A29. Bright: EN 10278 (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 34CrNiMo6 Round Bar
Pricing for Alloy Steel 34CrNiMo6 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 34CrNiMo6 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 34CrNiMo6 or 42CrMo4?
What ruling section can 34CrNiMo6 be used for?
Is 34CrNiMo6 the same as AISI 4340?
Can 34CrNiMo6 be nitrided or induction hardened?
How is 34CrNiMo6 heat treated, welded and machined?
What are the limits of 34CrNiMo6?
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