AISI 4140 Round Bar
AISI 4140 Round Bar is a versatile alloy steel product known for its excellent mechanical properties and high strength-to-weight ratio. Manufactured from chromium-molybdenum steel, this round bar offers superior toughness, wear resistance, and fatigue strength, making it ideal for demanding industrial applications. Precision-rolled and heat-treated, it ensures consistent dimensional accuracy and performance reliability.
This material type is widely utilized in the fabrication of shafts, gears, bolts, and heavy-duty machinery components due to its ability to withstand high stress and harsh environments. Its balanced composition allows for excellent hardenability and machinability, which facilitates custom processing and finishing operations. The round bar is often supplied in various diameters and lengths to meet specific engineering requirements.
Industries such as automotive, aerospace, oil and gas, and construction heavily rely on this alloy steel for critical parts that demand durability and resilience. Its toughness and fatigue resistance make it suitable for applications involving dynamic loads and impact conditions. Additionally, the materialβs compatibility with various surface treatments enhances its corrosion resistance, extending service life in challenging operational settings.
Export readiness is a key aspect of this product, with adherence to international standards such as ASTM A29/A29M ensuring quality and traceability. The round bars are typically packaged and shipped following stringent protocols to preserve their integrity during transit. Suppliers often provide detailed certification and test reports, facilitating seamless integration into global supply chains and compliance with customer specifications.
Our Approvals | Third Party Inspection
Lead Time
2β7 weeks depending on size
Delivery Terms
FOB, CIF, DDP
Shipping Modes
Sea / Air / Express
Why AISI 4140 Round Bar Are Preferred by Global Buyers
- β Factory Pricing: Direct manufacturer rates with bulk stock
- β Certified Quality: ISO & 3rd-party tested, EN 10204 certified
- β Export-Ready: Sea-worthy packaging for on-time delivery
- β Fast RFQs: Quick quotes for custom sizes & quantities
- β Traceability: 100% heat number tracking from raw material to finished product
Trusted by industries like oil & gas, petrochemicals, power, marine, and heavy engineering.
- Manufacturing Capacity: 500 MT / Month
- Export Experience: 50+ Years
- Countries Served: 50+
- Annual Export Volume: 5,500 MT
Table of Contents
- 1. What is AISI 4140 Round Bar
- 2. How to Choose the Right Manufacturer
- 3.Comparison of AISI 4140 Round Bar
- 4. Why Global Buyers Source from Super Metal Manufacturing Co.
- 5. Features
- 6. Technical Overview
- 7. Specifications
- 8. Available Grades
- 9. Available Sizes
- 10. Chemical Properties
- 11. Mechanical Properties
- 12. Physical & Thermal Properties
- 13. Electrical Resistivity
- 14. Equivalent Grades
- 15. Manufacturing Process & Heat Treatment
- 16. Various Types
- 17. Applications & Uses
- 18. Industries We Serve
- 19. Latest Price List
- 20. MOQ & Payment Terms
- 21.Export Packaging & Shipping
- 22. Cities We Supply in India
- 23. Countries We Export Worldwide
- 24. Our Certifications
- 25. Quality Inspection & Testing
- 26. Our Other Product Types
- 27. People Also Search For
- 28. Frequently Asked Questions
- 29. About Super Metal Manufacturing Co.
How to Choose the Right AISI 4140 Round Bar
India is home to hundreds of manufacturers ranging from small job shops to large ISO-certified exporters. International and domestic buyers typically evaluate manufacturers based on quality compliance, production capacity, export experience, and pricing transparency.
- Certification & international standards (ASME, ASTM, EN)
- Manufacturing capability vs trading activity
- Export documentation & inspection support
- Stock availability & lead time reliability
- Past supply experience in oil & gas, EPC & heavy industries
Comparison Factors Among AISI 4140 Round Bar
| Evaluation Factor | Small Local Suppliers | Trading Companies | ISO-Certified Manufacturers |
|---|---|---|---|
| Manufacturing Control | Limited | None | Full in-house / audited partners |
| International Standards | Basic | Depends on source | ASME / ASTM / EN |
| Inspection & MTCs | Limited | Inconsistent | EN 10204 3.1 / 3.2 |
| Export Experience | Low | Medium | 50+ countries |
| Risk for EPC Projects | High | Medium | Low |
International buyers typically prefer ISO-certified manufacturers for large-scale or critical applications due to better quality control, documentation, and lower project risk.
Why Global Buyers Choose Super Metal Manufacturing Co.
Super Metal Manufacturing Co. is a trusted ISO 9001:2015 certified manufacturer and global exporter of ferro alloys and metal products, supplying consistent, high-quality materials to customers across USA, UK, Europe, Middle East, Africa, and Asia-Pacific. Our focus on quality assurance, cost efficiency, and on-time delivery makes us a preferred sourcing partner for international buyers.
| Key Advantage | Buyer Benefit |
|---|---|
| ISO 9001:2015 Certified Manufacturing | Consistent quality with documented QA systems and process control |
| ASME / ASTM / EN Compliant Products | Globally accepted standards with EN 10204 3.1 / 3.2 MTCs |
| Lower Manufacturing & Sourcing Costs | Save up to 15β20% compared to European suppliers |
| Favorable Exchange Rate Advantage | Reduced landed cost for international importers |
| In-House Testing & Inspection Facilities | Strict chemical, mechanical & dimensional quality checks |
| Bulk Stock & High Production Capacity | Fast order fulfillment and stable supply for large projects |
| Custom Sizes & Drawing-Based Manufacturing | Products manufactured exactly to buyer specifications |
| Export-Grade Packaging & Global Logistics | Sea-worthy packing, palletization & worldwide shipping support |
| Faster Global Shipping Routes | Optimized logistics for Middle East, Africa & Southeast Asia |
| Technical & After-Sales Support | Project assistance, documentation & responsive RFQ handling |
| Trusted by Global Steel & EPC Companies | Proven export experience across 50+ countries |
Features of AISI 4140 Round Bar
- β High tensile strength for enhanced durability
- β Excellent fatigue resistance for dynamic applications
- β Good machinability for precise fabrication
- β Versatile alloy suitable for various industries
- β High hardenability for improved hardness after heat treatment
- β Corrosion resistance in various environments
Technical Overview of AISI 4140 Round Bar
| Product | Composition | Usage | Standards |
|---|---|---|---|
| AISI 4140 Round Bar | Carbon: 0.38-0.43%, Manganese: 0.75-1.00%, Chromium: 0.90-1.20%, Molybdenum: 0.15-0.25% | Used in manufacturing gears, shafts, axles, and other high-stress components | ASTM A29, ASTM A322, AMS 6349 |
| AISI 4140 Round Bar | Carbon: 0.38-0.43%, Manganese: 0.75-1.00%, Chromium: 0.90-1.20%, Molybdenum: 0.15-0.25% | Ideal for applications requiring high tensile strength and toughness | SAE J403, SAE J404 |
| AISI 4140 Round Bar | Carbon: 0.38-0.43%, Manganese: 0.75-1.00%, Chromium: 0.90-1.20%, Molybdenum: 0.15-0.25% | Commonly used in the oil and gas industry, as well as in heavy machinery | ASTM A829, DIN 42CrMo4 |
Specifications Table
| Material | AISI 4140 |
|---|---|
| Grades | 4140 |
| Standard | ASTM A829 |
| Size Range | 0.25" to 12.0" diameter |
| Length | Up to 20 feet |
| Form | Round Bar |
Available Grades Table
| Product | Composition | Applications |
|---|---|---|
| AISI 4140 Round Bar | Carbon: 0.38-0.43%, Chromium: 0.80-1.10%, Molybdenum: 0.15-0.25% | Used in the manufacturing of gears, axle shafts, and heavy-duty machinery components. |
| AISI 4140H Round Bar | Carbon: 0.40-0.44%, Chromium: 0.90-1.10%, Molybdenum: 0.15-0.25%, Higher hardness | Ideal for applications requiring high toughness and strength, such as axles and shafts. |
| AISI 4140 Prehard Round Bar | Carbon: 0.40-0.44%, Chromium: 0.90-1.10%, Molybdenum: 0.15-0.25%, Heat treated | Used in applications requiring high strength with reduced machining time. |
| AISI 4140QT Round Bar | Carbon: 0.40-0.44%, Chromium: 0.90-1.10%, Molybdenum: 0.15-0.25%, Quenched and tempered | Suitable for heavy-duty applications such as automotive and aerospace components. |
| AISI 4140 Alloy Steel Round Bar | Carbon: 0.38-0.43%, Chromium: 0.80-1.10%, Molybdenum: 0.15-0.25% | Commonly used in manufacturing mechanical parts and tools. |
Available Sizes of AISI 4140 Round Bar (MM)
| Size (MM) | Size (MM) |
|---|---|
| 10 | 20 |
| 30 | 40 |
| 50 | 60 |
| 70 | 80 |
| 90 | 100 |
| 110 | 120 |
| 130 | 140 |
| 150 | 160 |
| 170 | 180 |
| 190 | 200 |
Chemical Properties of AISI 4140 Round Bar
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.38 - 0.43 |
| Manganese (Mn) | 0.75 - 1.00 |
| Silicon (Si) | 0.15 - 0.40 |
| Chromium (Cr) | 0.90 - 1.20 |
| Molybdenum (Mo) | 0.15 - 0.25 |
| Phosphorus (P) | 0.04 (max) |
| Sulfur (S) | 0.04 (max) |
| Iron (Fe) | Balance |
Mechanical Properties of AISI 4140 Round Bar
| Property | Value |
|---|---|
| Tensile Strength (MPa) | 655 - 850 |
| Yield Strength (MPa) | 415 - 620 |
| Elongation at Break (%) | 17 - 22 |
| Reduction of Area (%) | 50 - 60 |
| Hardness (HB) | 197 - 300 |
AISI 4140 Round Bar β Physical & Thermal Properties
Density of AISI 4140 Round Bar
| Property | Metric | Imperial |
|---|---|---|
| Density | 7,850 kg/mΒ³ | 490 lb/ftΒ³ |
Melting Point of AISI 4140 Round Bar
| Property | Metric | Imperial |
|---|---|---|
| Melting Point | 1,540 Β°C | 2,804 Β°F |
Specific Heat of AISI 4140 Round Bar
| Specific Heat of AISI 4140 Round Bar | ||
|---|---|---|
| Specific Heat (J/kgΒ·K) | Temperature Range (Β°C) | Condition |
| 460 | 20 - 100 | Annealed |
| 500 | 100 - 400 | Tempered |
| 610 | 400 - 800 | Quenched |
Electrical Resistivity of AISI 4140 Round Bar
| Electrical Resistivity | ||
|---|---|---|
| Value (¡Ω·m) | Temperature (°C) | Treatment or Condition |
| 70 | 20 | As-rolled |
| 75 | 100 | |
| 80 | 200 | |
| 85 | 300 | |
| 90 | 400 | |
Equivalent of AISI 4140 Round Bar
| Standard | Werkstoff Nr. | UNS |
|---|---|---|
| ASTM AISI | 1.7225 | G41400 |
| DIN | 42CrMo4 | 1.7225 |
Manufacturing Process & Heat Treatment of AISI 4140 Round Bar
Annealing
The annealing process for AISI 4140 round bars involves heating the steel to a temperature range of 850Β°C to 900Β°C, followed by slow cooling in the furnace. This process reduces hardness, relieves internal stresses, and improves machinability, making it suitable for subsequent operations.
Forging
Forging of AISI 4140 is typically performed at temperatures between 1100Β°C and 1250Β°C. The steel is heated to a plastic state and then shaped under compressive forces. This process enhances the mechanical properties of the material and refines its grain structure, resulting in improved strength and toughness.
Hardening & Tempering
| Process | Temperature Range (Β°C) | Quenching Medium | Purpose |
|---|---|---|---|
| Hardening | 830Β°C - 870Β°C | Oil or Water | To increase hardness and strength by transforming austenite into martensite. |
| Tempering | 400Β°C - 700Β°C | N/A | To relieve stresses and reduce brittleness, improving toughness and ductility. |
| Stress Relieving | 600Β°C - 650Β°C | N/A | To eliminate residual stresses from the manufacturing process and enhance dimensional stability. |
The heat treatment processes of AISI 4140 round bars are critical for achieving desired mechanical properties, ensuring they meet the stringent requirements of various industrial applications.
Various Types
AISI 4140 Round Bar (Hot Rolled)
- Diameter: 20mm to 300mm
- Condition: Hot Rolled (HR)
- Applications: Automotive components, gear shafts, and axles
AISI 4140 Round Bar (Cold Finished)
- Diameter: 10mm to 200mm
- Condition: Cold Finished (CF)
- Applications: Precision machining, tool making, and aerospace
AISI 4140 Round Bar (Annealed)
- Diameter: 25mm to 150mm
- Condition: Annealed
- Applications: Heavy-duty machinery, structural components
AISI 4140 Round Bar (Quenched and Tempered)
- Diameter: 30mm to 250mm
- Condition: Quenched and Tempered (QT)
- Applications: High-stress applications, oil and gas industry
Applications & Uses
- Oil & Gas Industry
- Petrochemical Plants
- Water Treatment Plants
- Pharmaceutical Industry
- Food & Beverage Industry
- Automobile Industry
Industries We Serve
Our alloys are widely used across:
- Steel Plants
- Foundries & Casting Units
- Automobile Industry
- Shipbuilding & Marine
- Oil & Gas
- Engineering Components
- Heavy Industrial Machinery
latest Price List of AISI 4140 Round Bar
| Material Grade | Thickness | Price (USD / Kg) | Price (INR / Kg) |
|---|---|---|---|
| AISI 4140 Round Bar | 3 mm | $5.00 β $5.50 | βΉ415 β βΉ460 |
| AISI 4140 Round Bar | 6 mm | $4.80 β $5.30 | βΉ400 β βΉ450 |
| AISI 4140 Round Bar | 10 mm | $4.50 β $5.00 | βΉ375 β βΉ415 |
Note: Prices are indicative and may vary based on size, quantity, raw material cost, and delivery location. Contact us for the latest quotation for AISI 4140 Round Bar.
MOQ & Payment Terms
Minimum Order Quantity: 25β100 Kg depending on part size and grade.
Payment Terms: Depending On Grade and Quantity Size
Export Packaging & Shipping
- Seaworthy, fumigated wooden crates with waterproof inner lining
- Palletised packing with clear shipping marks and heat number identification
- Container stuffing supervision with loading photographs available on request
Cities We Suppllied In India
| Supply Cities | |||||
|---|---|---|---|---|---|
| Mumbai | Delhi | Pune | Chennai | Hyderabad | Bengaluru |
| Ahmedabad | Rajkot | Coimbatore | Kolkata | Bhopal | Surat |
We exported to 50+ countries worldwide.
| Exported Countries | |||||
|---|---|---|---|---|---|
| USA | UK | UAE | Germany | South Africa | Australia |
| Italy | Canada | Netherlands | Qatar | Saudi Arabia | Malaysia |
Our Certifications
We are a certified manufacturer and exporter, committed to strict quality control and international compliance standards.
Quality Inspection & Testing
At Super Metal Manufacturing Co., all products are checked through strict quality inspection and testing to meet international standards such as ASTM, ASME, EN, and DIN. This ensures consistent quality, accurate dimensions, and full material traceability.
- β Chemical composition testing
- β Mechanical tests such as tensile and hardness
- β Dimensional inspection as per standard tolerances
- β PMI, ultrasonic, and visual inspection (if required)
- β EN 10204 3.1 / 3.2 test certificates
- β Third-party inspection by SGS, TUV, BV, or Lloydβs
Our quality systems support reliable supply for oil & gas, petrochemical, power, marine, and heavy engineering projects.
People Also Search For
- AISI 4140 Steel Properties
- AISI 4140 Heat Treatment
- AISI 4140 vs AISI 4130
- AISI 4140 Round Bar Suppliers
- AISI 4140 Applications
Frequently Asked Questions
About Super Metal Manufacturing Co.
Super Metal Manufacturing Co. is a trusted name in the metal industry since 1965, specializing in the manufacturing and export of high-quality 4140, EN19, and 42CrMo4 round bars. With decades of experience, we have built a strong reputation for delivering precision-engineered, durable, and high-performance steel products to industries worldwide.
Our company is committed to excellence through a robust quality management system and strict quality control at every stage of production. From sourcing premium raw materials from reputed suppliers like SAIL and JSW to final delivery, every product undergoes rigorous testing including tensile testing, bend and rebend tests, chemical analysis, and ultrasonic testing to ensure superior performance and reliability.
We are accredited with ISO 9001 certification and are TUV certified, reflecting our commitment to international quality standards. Our state-of-the-art manufacturing facilities, advanced machinery, and skilled workforce enable us to deliver customized solutions tailored to client requirements.
- β 50+ years of industry experience in alloy steel and round bar manufacturing
- β Specialized in 4140, EN19, and 42CrMo4 high-performance round bars
- β ISO certified and TUV approved quality standards
- β Strict quality testing including ultrasonic and chemical analysis
- β Premium raw material sourcing from SAIL and JSW
- β Advanced manufacturing infrastructure with modern machinery
- β Custom-engineered solutions as per drawings and specifications
- β Global export capability with reliable delivery
- β Trusted by industries for critical and high-performance applications
Our Mission
Our mission is to deliver the highest-quality alloy steel round bars while maintaining excellence in precision, innovation, and customer satisfaction. We aim to empower industries worldwide by providing reliable and durable products that meet evolving manufacturing needs.
Our Vision
Our vision is to become a global leader in the manufacturing and export of premium-quality round bars, recognized for our product excellence, innovation, and commitment to exceeding customer expectations.