Alloy Steel 42CrMo4 Round Bar
➡️ UNS G41400 | EN 1.7225 | AISI 4140 | 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:
G41400
Wr. No.:
1.7225
MTC Available:
EN 10204 3.1
Product Description for Alloy Steel 42CrMo4 Round Bar
Alloy Steel 42CrMo4 Round Bar is a chromium-molybdenum quenched and tempered steel to EN 10083-3, with material number 1.7225. It contains about 0.38–0.45% carbon, 0.90–1.20% chromium and 0.15–0.30% molybdenum. It is one of the most widely used engineering steels in the world.
The steel offers a good balance of strength, toughness, hardenability and cost. After quenching and tempering it gives high tensile and yield strength with good fatigue resistance. It can also be induction or flame hardened, and nitrided, for extra surface hardness and wear resistance.
Hardenability is good for small and medium sections. For very large sections, nickel-bearing steels such as 34CrNiMo6 are often used instead. Molybdenum helps reduce temper embrittlement.
42CrMo4 stock bar is sold hot rolled or forged, in +A, +S or +QT condition. The UK counterparts are BS 970 708M40 and 709M40 (EN19), and the nearest American grade is AISI 4140. In Japan the matching grade is SCM440.
Common applications include shafts, axles, gears, crankshafts, spindles, bolts and studs, connecting rods, hydraulic cylinder rods, oil and gas tools, and machine parts. It is a standard choice for parts that need high strength and good toughness at moderate cost. Because it is stocked by almost every steel service centre, in sizes from small bright bars to forged bars of several hundred millimetres, buyers can usually get it quickly in both annealed and pre-hardened form. In China it is sold as 42CrMo to GB/T 3077, which is close but not identical in chemistry. Its 35 J impact minimum is lower than for nickel grades, so it is less suited to very cold service.
Common Applications of Alloy Steel 42CrMo4 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 42CrMo4 Round Bar
Standard
Country / Region
Grade
UNS
USA
UNS G41400
ASTM / AISI / SAE
USA
4140 / 4142
EN 10083-3
Europe
1.7225 (42CrMo4)
BS EN 10083-3
United Kingdom
708M40 / EN19
JIS G4053
Japan
SCM440 / SCM440H
GB/T 3077
China
42CrMo
KS D 3867
South Korea
SCM440 / SCM440H
AFNOR
France
42CD4
SS
Sweden
2244
GOST
Russia
35KHM / 38KHM
ISO 683-2
International
42CrMo4
Technical Specification for Alloy Steel 42CrMo4 Round Bar
Specification
Value
Unit
Material
Alloy steel
-
Grade
42CrMo4 / 1.7225
-
Standard
EN 10083-3 (forgings EN 10250-3)
-
Product Form
Round bar (hot rolled, forged or bright)
-
Diameter (supply range)
10–800 (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)
≈ 0.8
-
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 42CrMo4 Round Bar
Alloy Steel 42CrMo4 Round Bar is ordered to EN 10083-3, which covers alloy steels for quenching and tempering. Large 42CrMo4 shafts and rings can be ordered as forgings to EN 10250-3. The delivery condition must be stated, for example +A for machining or +QT for ready-to-use strength.
Hardening is usually done from about 820–860°C with oil or water quenching, followed by tempering at about 540–680°C. The tempering temperature is chosen to reach the required strength and toughness.
EN 10083-3 properties depend on the diameter of the bar, so the ruling section should be stated on the order. For 42CrMo4 bars above about 100 mm, ultrasonic testing is usually added.
With a carbon equivalent of about 0.80, 42CrMo4 is hard to weld. Welding needs preheat and post-weld heat treatment, and is usually avoided on quenched and tempered parts. The physical values for 42CrMo4 are reference data, useful for induction-hardening calculations.
For stock bar, the most common conditions are +A for machining and heat treatment by the customer, and +QT for parts that are machined and used without further hardening. Pre-hardened +QT bar is often sold in the range of about 28–32 HRC. Bright bars can be supplied to EN 10277 in h9 to h11 tolerance. For induction-hardened shafts, order +QT bar so that the core is already tough before the surface is hardened. For oil and gas parts, check whether the customer requires API or NACE hardness limits, which add extra hardness testing.
Chemical Composition for Alloy Steel 42CrMo4 Round Bar
Element
Symbol
Min
Max
Unit
Carbon
C
0.38
0.45
%
Silicon
Si
-
0.40
%
Manganese
Mn
0.60
0.90
%
Phosphorus
P
-
0.025
%
Sulfur
S
-
0.035
%
Chromium
Cr
0.90
1.20
%
Molybdenum
Mo
0.15
0.30
%
Chemical Composition
View the chemical composition and applicable material limits for 42CrMo4 Round Bar
The table shows the EN 10083-3 heat analysis limits for 42CrMo4. A controlled sulfur version, 42CrMoS4, is available for better machinability.
Carbon at 0.38–0.45% gives high hardness and strength after quenching. Chromium at 0.90–1.20% raises hardenability and adds wear resistance and some resistance to softening at temperature.
Molybdenum at 0.15–0.30% improves hardenability, raises strength after tempering and reduces temper embrittlement. It also improves creep strength at moderate temperatures.
In 42CrMo4, manganese also deoxidises the steel. Silicon is a deoxidiser. Phosphorus and sulfur in 42CrMo4 are held to 0.025% and 0.035% maximum to protect toughness. Carbon at 0.38–0.45% is the main difference from 34CrMo4 and 25CrMo4. The higher carbon raises the hardness that can be reached after quenching, which is why 42CrMo4 suits induction hardening, where surface hardness of about 54–58 HRC is common. Manganese at 0.60–0.90% and silicon up to 0.40% support hardenability. Because there is no nickel, the steel costs less than 34CrNiMo6, but its hardenability is lower, so the core of very large bars will not reach full strength. The controlled sulfur version 42CrMoS4 contains about 0.020–0.040% sulfur for easier machining.
Chromium at 0.90–1.20% also helps the steel respond well to nitriding.
Mechanical Properties for Alloy Steel 42CrMo4 Round Bar
Mechanical Property
Value
Unit
Yield Strength Re (+QT, d ≤ 16 mm)
≥ 900
MPa
Tensile Strength Rm (+QT, d ≤ 16 mm)
1100–1300
MPa
Yield Strength Re (+QT, 16 < d ≤ 40 mm)
≥ 750
MPa
Tensile Strength Rm (+QT, 16 < d ≤ 40 mm)
1000–1200
MPa
Yield Strength Re (+QT, 40 < d ≤ 100 mm)
≥ 650
MPa
Tensile Strength Rm (+QT, 40 < d ≤ 100 mm)
900–1100
MPa
Yield Strength Re (+QT, 100 < d ≤ 160 mm)
≥ 550
MPa
Tensile Strength Rm (+QT, 100 < d ≤ 160 mm)
800–950
MPa
Yield Strength Re (+QT, 160 < d ≤ 250 mm)
≥ 500
MPa
Tensile Strength Rm (+QT, 160 < d ≤ 250 mm)
750–900
MPa
Elongation A (+QT, 16 < d ≤ 40 mm)
≥ 11
%
Impact Energy KV at +20°C (+QT, d > 16 mm)
≥ 35
J
Hardness (+A, soft annealed)
≤ 241
HB
Mechanical Properties
Check the key mechanical properties and performance requirements of 42CrMo4 Round Bar
The values shown are EN 10083-3 minimum and range requirements for 42CrMo4 in the quenched and tempered (+QT) condition. Strength falls as bar diameter increases, because larger sections cool more slowly during quenching. Elongation and reduction of area rise as strength falls.
Minimum impact energy of 35 J at room temperature applies for diameters above 16 mm. In the soft annealed condition, hardness is limited to 241 HB for good machinability.
Surface hardening by induction or flame, and nitriding, can raise surface hardness for wear parts. For 42CrMo4 parts, use the strength band for the finished diameter, not the bar stock size, when it is smaller. EN 10083-3 sets the +QT minimum yield strength at 900 MPa up to 16 mm, 750 MPa for 16–40 mm, 650 MPa for 40–100 mm, 550 MPa for 100–160 mm and 500 MPa for 160–250 mm. Tensile strength is given as a range for each size band. The 35 J impact requirement is lower than for 25CrMo4 or 34CrNiMo6, which reflects the higher carbon content. If a part needs better low-temperature toughness, order impact tests at the service temperature or consider a nickel-bearing grade.
Dimension / Sizes for Alloy Steel 42CrMo4 Round Bar
Dimension / Size
Value
Unit
Available Diameter Range (supply capability)
10–800 (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 42CrMo4 Round Bar
Pricing for Alloy Steel 42CrMo4 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 42CrMo4 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 42CrMo4 or 34CrNiMo6?
Is 42CrMo4 the same as AISI 4140?
What hardness can 42CrMo4 reach by induction hardening?
Can I buy 42CrMo4 pre-hardened?
How is 42CrMo4 heat treated, welded and machined?
What are the limits of 42CrMo4?
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