34CrNiMo6 Alloy Steel | DIN 1.6582 | High-Strength Nickel-Chromium-Molybdenum Steel Supplier

34CrNiMo6 is a premium nickel-chromium-molybdenum high-strength steel manufactured to DIN EN 10083-3 standards, recognized as one of the most important quenched and tempered steels for highly stressed components. With 0.30-0.38% carbon, 1.30-1.70% nickel, 1.30-1.70% chromium, and 0.15-0.30% molybdenum, it delivers an exceptional combination of high strength, outstanding toughness, and superior fatigue resistance. What sets this grade apart is its balanced composition, which provides excellent hardenability even in very large cross-sections. Thanks to its significant nickel content, it maintains outstanding toughness at high strength levels—making it ideal for components subjected to extreme mechanical loads.

This versatile grade is also designated as similar to AISI 4340, 40CrNiMo in China, SNCM439 in Japan, and 817M40 in the UK. Whether for crankshafts, turbine components, heavy-duty gears, or high-strength fasteners, it delivers reliable performance under extreme operating conditions. Available annealed for machinability or quenched and tempered for immediate use.

Material Shape and Size

1.Round Bar

Flat Bar

Equivalent Grade

Standard System	Country/Region	Equivalent Grade	Common Search Terms
DIN EN	Germany	1.6582, 34CrNiMo6	34CrNiMo6 steel, DIN 1.6582
AISI/ASTM	USA	4340 (similar)	4340 steel, AISI 4340
JIS	Japan	SNCM439	SNCM439 steel, JIS SNCM439
GB	China	40CrNiMo, 40CrNiMoA	40CrNiMo steel, GB 40CrNiMo
BS	UK	817M40, EN24	817M40 steel
ISO	International	34CrNiMo6	ISO 34CrNiMo6 equivalent

Chemical Composition

Element	C	Si	Mn	P	S	Cr	Ni	Mo
Content (%)	0.30-0.38	≤0.40	0.50-0.80	≤0.035	≤0.035	1.30-1.70	1.30-1.70	0.15-0.30

Mechanical Property

MECHANICAL PROPERTY	METRIC VALUE	IMPERIAL VALUE
Hardness (Annealed)	≤269 HB	≤269 HB
Hardness (Quenched & Tempered)	28 – 34 HRC	28 – 34 HRC
Tensile Strength (σb)	700 – 1200 MPa	101.5 – 174 ksi
Yield Strength (σ0.2)	≥490 – 940 MPa	≥71 – 136 ksi
Elongation (δ5)	8 – 14 %	8 – 14 %
Reduction of Area (ψ)	40 – 52 %	40 – 52 %
Impact Toughness (KV, 20°C, Longitudinal)	≥21 – 45 J	≥15.5 – 33.2 ft·lb

Delivery Condition

Black Surface, Bright Surface, Turned Surface, Grinded Surface, Poblished surface.

Application

Crankshafts and Eccentric Shafts: Highly stressed rotating components for engines and compressors requiring exceptional fatigue strength
Gear Components: Transmission gears, pinions, and gear shafts for heavy-duty applications in automotive, industrial, and marine sectors
Turbine Components: Turbine shafts, blades, and rotors for power generation and aerospace applications
Heavy Machinery: Highly stressed machine parts for construction, mining, and industrial equipment
Cold Heading and Extrusion: Components manufactured by cold heading or cold extrusion, subsequently quenched and tempered
Pressure Vessel Components: Steel products for unfired pressure vessels requiring high strength and reliability
Aerospace Components: Landing gear parts, structural components, and engine mounts
Oil and Gas Industry: Drill collars, tool joints, and downhole components for high-pressure service
Fasteners and Connectors: High-strength bolts, studs, and couplings for critical applications

Heat Treatment & Processing

Heat Treatment:

Soft Annealing
Heat to 650-700°C, hold 2-4 hours, slow furnace cool. Optimized for machinability.

Normalizing
Heat to 840-880°C, hold adequate time, air cool. Refines grain structure before hardening.

Hardening (Austenitizing)
Heat to 830-860°C (1526-1580°F). Soak time proportional to section size. Protect against oxidation and decarburization.

Quenching
Oil quench for most sections

Polymer or water quench possible for simple shapes with caution

Quench to 50-70°C, then temper immediately

Tempering
Temper immediately after quenching. Double tempering recommended for critical applications. Hold minimum 1 hour per 25mm section thickness each temper.

Processing Guide:

Surface Hardening
Can be flame or induction hardened after quenching and tempering to achieve enhanced surface wear resistance .

Cold Heading and Extrusion
Suitable for cold heading and cold extrusion processes, followed by subsequent quenching and tempering or induction hardening .

Quality Inspection & Control

Full-process control: Raw material inspection (certificate, composition); production inspection (composition, mechanical properties, 100% UT, dimensional, surface); finished product inspection (MTC EN 10204 3.1, reports).

Our Advantages

Strong Production Capacity: 10,000 tons/year, advanced equipment.
Adequate Stock: 600+ tons standard specs (3-7 days delivery); custom specs 15-30 days.
Custom Processing: One-stop sawing, milling, drilling, polishing, heat treatment.
Strict Quality Control: Full-process inspection, professional team/equipment.
Global Supply: Container/LCL shipment, anti-rust packaging, on-time delivery.
Professional Technical Support: Senior engineers guide material selection, heat treatment, processing.