Description: BBN steel is a well-known steel manufacturer and service provider in China, GB/T 3077 42CrMo steel plate is our superior product, we are favored by customers with high quality, competitive price and excellent service
Payment Terms: L/C, T/T, D/P, Western Union, Paypal, Money Gram
Chinese High-Performance Alloy Structural Steel | Equivalent to ASTM 4140 / JIS SCM440 / EN 42CrMo4 (1.7225) | Excellent Strength, Toughness & Hardenability | MTC & Third-Party Inspection
High Strength & Toughness42CrMo delivers high strength and good toughness after quenching and tempering, with no obvious temper brittleness for stable service.
Excellent HardenabilityCr-Mo alloying gives stable hardenability and strong low-temperature impact toughness for heavy-duty dynamic loads.
Stock & Fast DeliveryPlates 8–250 mm in stock, MTC available, custom cutting and third-party inspection supported.
01Product Overview & Specifications
GB/T 3077 42CrMo is a high-performance Chinese alloy structural steel featuring superior strength, good toughness and excellent hardenability with no obvious temper brittleness. After quenching and tempering it delivers a high fatigue limit, strong multi-impact resistance and stable low-temperature impact toughness.
Ideal for heavy-duty mechanical structural applications, 42CrMo alloy steel plate is the preferred material for engineering machinery, automobile manufacturing, petroleum machinery and high-precision mechanical transmission components that work under complex alternating loads, torsion, friction and high pressure.
Promptly (Stock) / Custom production: 10 – 40 working days
Stock Status
Available
Certification
Mill Test Certificate (MTC) available, third-party inspection supported
Payment Terms
T/T, L/C At Sight
02Equivalent International Steel Grades
42CrMo is a mainstream high-strength alloy structural steel with widely used international equivalent grades, ensuring reliable cross-standard substitution for global mechanical manufacturing projects.
Standard System
Equivalent Grade
GB/T 3077 (China)
42CrMo
JIS (Japan)
SCM440
ASTM (USA)
4140
EN 10083-3 (EU)
42CrMo41.7225
Note: These equivalent grades share the Cr-Mo alloying concept and comparable hardenability, yet differ in impurity limits, testing and certification. For design-critical applications, verify detailed specifications before substitution. BBN technical team can assist with grade matching.
03Grade Designation & Meaning
The GB/T 3077 designation 42CrMo encodes the carbon level and the alloying elements of this chromium-molybdenum steel.
42
42 — Carbon Content
Indicates a mean carbon content of approximately 0.42% (100 × C%) for high strength after hardening.
Cr
Cr — Chromium
Chromium improves hardenability, hardness and wear resistance of the heat-treated steel.
Mo
Mo — Molybdenum
Molybdenum raises high-temperature strength and hardenability, and avoids obvious temper brittleness.
4
4 — Grade Index
Quality / sequence index within the GB chromium-molybdenum alloy steel family.
42CrMo (GB) vs 42CrMo4 (EN 10083-3, 1.7225): Both belong to the same Cr-Mo family with near-identical composition and heat-treatment response, and are cross-substitutable for most structural applications. 42CrMo4 is the European designation of the same grade.
04Chemical Composition
Cast analysis limits of 42CrMo per GB/T 3077 (values in %, unless a range is given).
Element
Content (%)
C (Carbon)
0.38 – 0.45
Si (Silicon)
0.40 max
Mn (Manganese)
0.60 – 0.90
P (Phosphorus)
0.035 max
S (Sulfur)
0.035 max
Cr (Chromium)
0.90 – 1.20
Mo (Molybdenum)
0.15 – 0.30
Note: Values per GB/T 3077. Carbon is given as 0.38 – 0.45 (the standard range; the source listed 0.38–0.25, which is corrected — a carbon range cannot have its minimum greater than its maximum). Chromium and molybdenum provide the hardenability and high-temperature strength. The exact heat analysis of each batch is stated in its Mill Test Certificate (MTC).
05Mechanical Properties
Mechanical properties of 42CrMo in the quenched and tempered condition per GB/T 3077 (reference values; actual results depend on section size and heat-treatment parameters).
930 MPaMin. Yield Rp0.2Quenched & tempered
1080 MPaMin. Tensile RmQuenched & tempered
Mechanical properties of 42CrMo (GB/T 3077):
Grade
Thickness (mm)
Yield Rp0.2 (MPa, min)
Tensile Rm (MPa, min)
Hardness HBW
42CrMo
6 – 50
930
1080
—
42CrMo
50 – 200
930
1080
—
Note: 42CrMo is a heat-treatable steel; the values above are achieved after quenching and tempering and vary with section thickness and tempering temperature. Hardness (HBW) depends on the tempering temperature and is confirmed in the MTC for your required condition.
06Product Types, Processing & Service
BBN Steel stocks a wide range of 42CrMo high-strength alloy steel plates with full traceability and official Mill Test Certificates, ideal for heavy-load mechanical structural parts, bearing components, high-strength gears and shaft parts.
1
Alloy Steel Plate
Hot-rolled plates 8–250 mm thick, 1500–4050 mm wide, 3000–15000 mm long; customizable fixed length.
2
Stock & Traceability
Plates available in stock, fully traceable, MTC provided upon purchase.
3
Cutting & Processing
Custom cutting, heat treatment and machining per your drawings; third-party inspection supported.
1
Fast Delivery
Common sizes shipped promptly from stock; custom production 10–40 working days.
2
MTC & Inspection
Mill Test Certificates available; third-party quality inspection supported.
3
Flexible Payment
T/T and L/C at sight accepted for your convenience.
4
Tech Consultation
Grade matching and processing advice from our sales & technical team.
GB/T 3077 42CrMo alloy steel plates, 8–250 mm thickness, 1500–4050 mm width, 3000–15000 mm length
High strength, good toughness, excellent hardenability, no obvious temper brittleness
MTC available, third-party inspection supported, full material traceability
T/T and L/C at sight payment, stock available, custom cutting and processing
Get Your GB/T 3077 42CrMo Steel Plate Quotation Now
Send us your dimensions (thickness × width × length), quantity, heat-treatment and hardness requirements. We will reply with stock status, competitive factory price and complete certification.
BBN Steel has established a complete set of production and supplier management system processes to ensure the improvement of product quality and better service to users.
Production Control
BBN Steel has established a complete production quality control process to ensure every link from research and development to mass production.
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Our supplier selection will consider factors such as health and safety, ethics, environmental protection, price and quality to better serve customers.
Certification & Patent
We have successively won various international authoritative certifications, GB /T19001-ISO9001: 2000 quality management system was implemented.
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Address: HIGH-TECH DEVELOPMENT ZONE, ZHENGZHOU, CHINA
