Alloy Steel 4140 Class BB and BC
Alloy Steel 4140 Class BB and BC
Apar Alloys, a leading stockist and supplier, offers Alloy Steel 4140 Class BB and BC, a premium chromium-molybdenum steel known for its superior strength, toughness, and wear resistance. Widely used in engineering, automotive, oil & gas, and heavy machinery sectors, it is ideal for manufacturing high-stress components such as shafts, gears, bolts, and crankshafts, delivering dependable performance under demanding conditions.
With excellent hardenability, uniform mechanical properties, and machinability, this grade withstands fatigue, impact, and elevated temperature environments. The combination of chromium and molybdenum ensures enhanced resistance to wear, abrasion, and oxidation, while its adaptability to heat treatment processes like quenching and tempering allows precise control over strength and toughness. Alloy Steel 4140 Class BB and BC remains a trusted material for critical, load-bearing industrial applications.
Specifications
| Grade | AISI | UNS | ASTM A276 / A479 | ASTM A182 | EN (W-Nr) | DIN Spec |
|---|---|---|---|---|---|---|
| 4140 (Class BB) | AISI 4140 | G41400 | ASTM A276 / A479 | ASTM A182 | 1.7225 | 42CrMo4 |
| 4140 (Class BC) | AISI 4140 | G41400 | ASTM A276 / A479 | ASTM A182 | 1.7225 | 42CrMo4 |
General Characteristics
Medium carbon chromium-molybdenum alloy steel
High strength and toughness in heat-treated condition
Excellent fatigue and impact resistance
Good hardenability and dimensional stability after machining
Suitable for quenching, tempering, and surface hardening
Reliable performance in dynamic and high-stress environments
Chemical Composition (nominal) %
| Element | C | Si | Mn | P | S | Cr | Ni | Mo | Fe |
|---|---|---|---|---|---|---|---|---|---|
| 4140 Class BB | 0.38–0.43 | 0.15–0.35 | 0.65–0.95 | ≤0.035 | ≤0.040 | 0.80–1.10 | ≤0.25 | 0.15–0.25 | Balance |
| 4140 Class BC | 0.38–0.43 | 0.15–0.35 | 0.65–0.95 | ≤0.035 | ≤0.040 | 0.80–1.10 | ≤0.25 | 0.15–0.25 | Balance |
Applications
Transmission shafts and drive components
Gears, studs, and heavy-duty fasteners
Tool holders and hydraulic parts
Machine and crank components
Powertrain and oilfield equipment
Structural and automotive applications
Advantages
- High tensile and yield strength with superior ductility
- Excellent wear and fatigue resistance under dynamic loads
- Stable mechanical properties after heat treatment
- Reliable machinability and consistent dimensional control
- Suitable for precision-engineered and high-load parts
- Extended component life and low maintenance requirements
Mechanical Properties (Typical at Room Temperature)
| Property | Value |
|---|---|
| Tensile Strength (MPa) | 850 – 1000 |
| Yield Strength (MPa) | 655 |
| Elongation (%) | 20 |
| Hardness (Brinell) | 197 – 255 HB |
Why Choose Apar Alloys
At Apar Alloys, we combine technical expertise with a customer-centric approach. Our extensive stock and global sourcing partnerships ensure clients receive certified materials that comply with international standards and specific application requirements.
Reliable Stockist & Supplier
We maintain a ready-to-dispatch inventory of materials, providing fast and dependable delivery for every client.
Sourced from Reputed Global Mills
All materials are sourced from trusted international suppliers, ensuring consistent quality and reliability.
Comprehensive Quality Assurance
Each product undergoes thorough inspections with traceable certifications to meet stringent quality standards.
Custom Sizes & Finishing
We offer tailored solutions, including custom sizing, cut-to-length, and finishing to fulfill client requirements.
Competitive Pricing & Dependable Delivery
Apar Alloys provides cost-effective solutions while maintaining timely deliveries across industries.
Dedicated Client Support
Our experienced team offers personalized assistance, fostering long-term relationships built on trust and reliability.
Get in Touch
Contact Us
Looking for a trusted supplier for Alloy Steel 4140 Class BB and BC materials? Contact us today for quotes, material specifications, or customized supply solutions for Alloy Steel Round Bars and Pipes.
[Call] +91 98333 89128
301, 3rd floor, A WING, Krishvi Escape, Near Vinay Health Home, Fanaswadi Bhuleshwar, Mumbai - 400002.
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