AISI 4340 Forged Black Flat Bar
AISI 4340 Forged Black Flat Bar is a high-strength alloy steel product known for its excellent mechanical properties and durability. Manufactured through a forging process, this flat bar features enhanced toughness and fatigue resistance, making it suitable for demanding industrial applications. The black finish indicates a protective oxide layer that helps reduce corrosion and surface wear during handling and initial service periods.
Composed primarily of nickel, chromium, and molybdenum, this grade of alloy steel offers superior tensile strength and hardenability compared to standard carbon steels. The flat barβs dimensional accuracy and uniform cross-section ensure consistent performance in fabrication and machining operations. Typically available in various thicknesses and widths, it can be customized to meet specific engineering requirements.
Widely used in sectors such as aerospace, automotive, heavy machinery, and defense, this alloy flat bar serves critical roles in components like shafts, gears, bolts, and structural parts that demand high fatigue strength and impact resistance. Its ability to maintain mechanical integrity under high stress and variable temperatures makes it a preferred choice for load-bearing and safety-critical applications.
Manufacturers preparing this product for export adhere to international standards, including ASTM and ISO certifications, ensuring quality and traceability. The supply chain is optimized for global distribution, providing seamless logistics support and compliance with customs regulations. This readiness facilitates timely delivery to industrial buyers worldwide, supporting large-scale projects and long-term procurement strategies.
Our Approvals | Third Party Inspection
Lead Time
2β7 weeks depending on size
Delivery Terms
FOB, CIF, DDP
Shipping Modes
Sea / Air / Express
Why AISI 4340 Forged Black Flat 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 4340 Forged Black Flat Bar
- 2. How to Choose the Right Manufacturer
- 3.Comparison of AISI 4340 Forged Black Flat 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 4340 Forged Black Flat 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 4340 Forged Black Flat 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 4340 Forged Black Flat Bar
- β High tensile strength up to 120,000 psi
- β Excellent toughness and fatigue resistance
- β Superior machinability compared to other alloy steels
- β Ideal for heavy-duty applications and structural components
- β Good wear resistance and hardenability
- β Available in various sizes and thicknesses for customization
Technical Overview of AISI 4340 Forged Black Flat Bar
| Product | Composition | Usage | Standards |
|---|---|---|---|
| AISI 4340 Forged Black Flat Bar | Carbon: 0.38-0.43%, Manganese: 0.60-0.90%, Chromium: 0.70-0.90%, Nickel: 1.65-2.00%, Molybdenum: 0.15-0.25% | High-strength applications, aerospace components, automotive parts, and heavy machinery. | ASTM A829, AMS 6415, SAE J404 |
| AISI 4340 Forged Black Flat Bar | Carbon: 0.38-0.43%, Manganese: 0.60-0.90%, Chromium: 0.70-0.90%, Nickel: 1.65-2.00%, Molybdenum: 0.15-0.25% | Used in applications requiring high tensile strength and toughness, including gears and shafts. | ASTM A829, AMS 6415, SAE J404 |
| AISI 4340 Forged Black Flat Bar | Carbon: 0.38-0.43%, Manganese: 0.60-0.90%, Chromium: 0.70-0.90%, Nickel: 1.65-2.00%, Molybdenum: 0.15-0.25% | Ideal for applications in the oil and gas industry, as well as military and defense sectors. | ASTM A829, AMS 6415, SAE J404 |
Specifications Table
| Material | AISI 4340 |
|---|---|
| Grades | 4340 |
| Standard | ASTM A829 |
| Size Range | 1" to 6" width x 0.25" to 2" thickness |
| Length | Up to 20 feet |
| Form | Forged Black Flat Bar |
Available Grades Table
| Product | Composition | Applications |
|---|---|---|
| AISI 4340 Forged Black Flat Bar | Carbon (0.38 - 0.43%), Manganese (0.60 - 0.90%), Phosphorus (max 0.04%), Sulfur (max 0.05%), Chromium (0.70 - 0.90%), Nickel (1.65 - 2.00%), Molybdenum (0.15 - 0.25%) | Aerospace components, automotive applications, heavy machinery, and high-stress structural components |
| AISI 4340 Forged Black Flat Bar | Similar to above with variations in nickel and chromium for specific properties | Oil and gas drilling equipment, military applications, and aerospace fittings |
| AISI 4340 Forged Black Flat Bar | Specialized heat-treated versions for enhanced durability | High-performance automotive parts, aerospace landing gear, and heavy-duty machinery components |
| AISI 4340 Forged Black Flat Bar | Variants with increased hardenability for specific applications | Mining equipment, high-strength fasteners, and structural components in cranes |
| AISI 4340 Forged Black Flat Bar | Custom formulations tailored for specific industrial requirements | Railway axles, pressure vessels, and specialized tooling |
Available Sizes of AISI 4340 Forged Black Flat Bar (MM)
| Size (MM) | Size (MM) |
|---|---|
| 25 x 5 | 100 x 20 |
| 30 x 6 | 125 x 25 |
| 40 x 8 | 150 x 30 |
| 50 x 10 | 200 x 40 |
| 60 x 12 | 250 x 50 |
| 75 x 15 | 300 x 60 |
| 80 x 16 | 350 x 70 |
| 90 x 18 | 400 x 80 |
| 100 x 20 | 450 x 90 |
| 120 x 25 | 500 x 100 |
Chemical Properties of AISI 4340 Forged Black Flat Bar
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.38 - 0.43 |
| Manganese (Mn) | 0.60 - 0.90 |
| Silicon (Si) | 0.15 - 0.40 |
| Chromium (Cr) | 0.70 - 0.90 |
| Nickel (Ni) | 1.65 - 2.00 |
| Molybdenum (Mo) | 0.15 - 0.25 |
| Phosphorus (P) | β€ 0.035 |
| Sulfur (S) | β€ 0.040 |
Mechanical Properties of AISI 4340 Forged Black Flat Bar
| Property | Value |
|---|---|
| Tensile Strength (MPa) | 1080 - 1180 |
| Yield Strength (MPa) | 930 - 1030 |
| Elongation (% in 50 mm) | 12 - 15 |
| Reduction of Area (%) | 50 |
| Hardness (HB) | 300 - 350 |
AISI 4340 Forged Black Flat Bar β Physical & Thermal Properties
Density of AISI 4340 Forged Black Flat Bar
| Property | Metric | Imperial |
|---|---|---|
| Density | 7,850 kg/mΒ³ | 490 lb/ftΒ³ |
Melting Point of AISI 4340 Forged Black Flat Bar
| Property | Metric | Imperial |
|---|---|---|
| Melting Point | 1,400 - 1,540 Β°C | 2,552 - 2,804 Β°F |
Specific Heat of AISI 4340 Forged Black Flat Bar
| Specific Heat of AISI 4340 Forged Black Flat Bar | ||
|---|---|---|
| Specific Heat (J/kgΒ·K) | Temperature Range (Β°C) | Condition |
| 500 | 20 - 100 | Room Temperature |
| 480 | 100 - 300 | Elevated Temperature |
| 450 | 300 - 600 | High Temperature |
Electrical Resistivity of AISI 4340 Forged Black Flat Bar
| Electrical Resistivity | ||
|---|---|---|
| Value (¡Ω·m) | Temperature (°C) | Treatment or Condition |
| 72 | 20 | Quenched and Tempered |
| 75 | 100 | |
| 78 | 200 | |
| 80 | 300 | |
| 82 | 400 | |
Equivalent of AISI 4340 Forged Black Flat Bar
| Standard | Werkstoff Nr. | UNS |
|---|---|---|
| ASTM A829 | 34CrNiMo6 | G43400 |
| EN 10083-3 | 42CrMo4 | 1.7225 |
Manufacturing Process & Heat Treatment of AISI 4340 Forged Black Flat Bar
Annealing
The annealing process for AISI 4340 involves heating the material to a temperature range of 800-900Β°C, followed by a slow cooling process. This treatment is designed to reduce hardness, improve ductility, and relieve internal stresses within the steel, making it easier to machine and work with in subsequent processes.
Forging
AISI 4340 is typically forged at temperatures between 1000-1150Β°C. During the forging process, the steel is shaped into flat bars through mechanical deformation while maintaining its integrity and enhancing its mechanical properties. Forging improves the grain structure and overall strength of the material.
Hardening & Tempering
| Process | Temperature Range (Β°C) | Quenching Medium | Purpose |
|---|---|---|---|
| Hardening | 850-900 | Oil | Increase hardness and strength |
| Tempering | 400-600 | Air | Reduce brittleness and improve toughness |
| Stress Relieving | 600-650 | Air | Relieve internal stresses from previous processes |
The heat treatment processes of hardening and tempering are crucial in achieving the desired mechanical properties of AISI 4340 forged black flat bars, ensuring their performance in demanding applications.
Various Types
AISI 4340 Forged Black Flat Bar - Standard
- Width: 2 inches, Thickness: 0.25 inches, Length: 12 feet
- Condition: Hot Rolled
- Applications: Automotive, Aerospace, Machinery Components
AISI 4340 Forged Black Flat Bar - Heavy Duty
- Width: 3 inches, Thickness: 0.5 inches, Length: 10 feet
- Condition: Annealed
- Applications: Heavy Machinery, Tooling, Structural Components
AISI 4340 Forged Black Flat Bar - Custom
- Width: 4 inches, Thickness: 0.75 inches, Length: 8 feet
- Condition: Quenched and Tempered
- Applications: High-Stress Applications, Oil and Gas Industry
AISI 4340 Forged Black Flat Bar - Aerospace Grade
- Width: 2.5 inches, Thickness: 0.375 inches, Length: 6 feet
- Condition: Solution Treated
- Applications: Aerospace Components, High-Performance Parts
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 4340 Forged Black Flat Bar
| Material Grade | Thickness | Price (USD / Kg) | Price (INR / Kg) |
|---|---|---|---|
| AISI 4340 Forged Black Flat Bar | 3 mm | $3.20 β $3.50 | βΉ265 β βΉ290 |
| AISI 4340 Forged Black Flat Bar | 6 mm | $3.00 β $3.25 | βΉ250 β βΉ270 |
| AISI 4340 Forged Black Flat Bar | 10 mm | $2.80 β $3.00 | βΉ230 β βΉ250 |
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 4340 Forged Black Flat 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 Forged Black Flat Bar
- AISI 1045 Steel Flat Bar
- AISI 4130 Alloy Steel Flat Bar
- AISI 5160 Spring Steel Flat Bar
- AISI 8620 Steel Flat Bar
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.