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AISI 4142 Alloy Steel | UNS G41420 Product Guide
- John
In the world of manufacturing and engineering, 4142 steel is a cornerstone for parts that require robust performance under stress. At SteelPro Group, we not only provide high-quality 4142 steel but also offer custom sizing and processing services.
Eager to explore the realm of 4142 alloy steel? Let’s explore how this exceptional material can elevate your projects.
What Is 4142 Steel?
AISI 4142 is a medium-carbon alloy steel known for its excellent toughness, wear resistance, and strength. In its annealed state, 4142 is easy to machine. It contains resistance to creep at temperatures up to 1000°F (537°C). It is commonly utilized in scenarios that demand exceptional performance under intense pressure. Common uses include camshafts, drill rods, bolts, couplings, spindles, piston rods, gears, valves, and other heavy-duty components.
AISI 4142 Steel Equivalent Grades
SteelPro Group ensures the compliance of our 4142 products with international standards. This ensures that our products comply with the most stringent quality standards for a wide range of uses.
| Standard | Equivalent Grade |
| GB | 42CrMo |
| ISC | A30422 |
| ISO | 42CrMo4 |
| ASTM/AISI | 4140, 4142 |
| UNS | G41400, G41420 |
| EN/DIN | 42CrMo4 |
| Number | 1.7225 |
| JIS | SCM440, SCM440H |
- Other equivalents of 4142 steel:
UNS G41420, ASTM A322, ASTM A331, ASTM A505, ASTM A519, ASTMA547, SAE J404, SAE J412, SAE J770
4142 Steel Chemical Composition
| Elements | Content (wt%) |
| Carbon (C) | 0.40~0.45 |
| Silicon (Si) | 0.15~0.35 |
| Manganese (Mn) | 0.75~1.00 |
| Phosphorus (P) | ≤0.035 |
| Sulfur (S) | ≤0.04 |
| Chromium (Cr) | 0.80~1.10 |
| Molybdenum (Mo) | 0.15~0.25 |
4142 Steel Mechanical Properties
| Property | Metric | English |
| Hardness, Brinell | 187~229 | 187~229 |
| Hardness, Knoop | 230 | 230 |
| Hardness, Rockwell B | 94 | 94 |
| Hardness, Rockwell C | 15 | 15 |
| Hardness, Vickers | 218 | 218 |
| Modulus of Elasticity | 206 GPa | 29900 ksi |
| Bulk Modulus | 163 GPa | 23600 ksi |
| Poisson’s Ratio | 0.29 | 0.29 |
| Machinability | 65% | 65% |
| Shear Modulus | 80.0 GPa | 11600 ksi |
- The mechanical properties in the table are for 4142 steel in the annealed and cold-drawn condition. These properties can vary with different heat treatments, such as quenching or tempering, which affect hardness, tensile strength, and performance. The values should be viewed as reference points.
4142 Steel Physical Properties
| Property | Metric | English |
| Density | 7.85 g/cm³ | 0.284 lb/in³ |
| Melting Point | 1420°C | 2588°F |
| Specific Gravity | 7.85 | 0.284 |
4142 Steel Thermal Properties
| Property | Metric | English |
| Specific Heat Capacity | 0.473 J/g-°C | 0.113 BTU/lb-°F |
| Thermal Conductivity | 42.6 W/m-K | 296 BTU-in/hr-ft²-°F |
4142 Steel Applications
| Industry | Applications |
| Automotive | Crankshafts, connecting rods, transmission gears, valve springs, suspension parts |
| Aerospace | Landing gear parts, aircraft structural components, engine components |
| Industrial Machinery | Gears, shafts, bearings, spindles, hydraulic parts |
| Tooling | Drill bits, cutting tools, forging dies |
| Military and Defense | Gun barrels, high-strength bolts, components subjected to high stress/fatigue |
| Oil and Gas | Drill rods, hydraulic cylinders |
4142 Steel Product Forms and Size
We provide 4142 steel in a range of shapes and dimensions to meet various needs. Our selection includes round bars, flat bars, plates, forged bars, sheets, and tubes.
We also offer personalized sizing and precise length cutting services to accommodate specific project needs. This flexibility ensures we can deliver precisely what you need for your application.
| Product Form | Size Range (Metric) | Size Range (English) |
| Round Bars | Diameter: 10~300 mmLength: 1000~6000 mm | Diameter: 0.39~11.81 inLength: 39.37~236.22 in |
| Flat Bars | Width: 20~500 mmThickness: 3~50 mmLength: 1000~6000 mm | Width: 0.79~19.69 inThickness: 0.12~1.97 inLength: 39.37~236.22 in |
| Plate | Thickness: 5~100 mmLength: 1000~6000 mm | Thickness: 0.20~3.94 inLength: 39.37~236.22 in |
| Forged Bars | Diameter: 50~500 mmLength: 1000~6000 mm | Diameter: 1.97~19.69 inLength: 39.37~236.22 in |
| Sheets | Thickness: 1~12 mmLength: 1000~4000 mm | Thickness: 0.04~0.47 inLength: 39.37~157.48 in |
| Tube/Pipe | Diameter: 20~200 mmThickness: 2~20 mmLength: 1000~6000 mm | Diameter: 0.79~7.87 inThickness: 0.08~0.79 inLength: 39.37~236.22 in |
4142 Steel Forging Process
Forging 4142 steel begins by heating it 1,150 to 1,200°C (2,100 to 2,190°F). Once the desired shape is achieved, the steel is slowly cooled to prevent internal stresses that could weaken the material.
4142 Steel Heat Treatment
- Quenching: First, the steel is heated to 850 to 880°C (1,560 to 1,620°F) and rapidly cooled, often in oil or water, to lock in hardness.
- Tempering: Following quenching, reheat the steel to 400 to 650°C (750 to 1,200°F). This step reduces brittleness while retaining the necessary strength for practical applications.
4142 Steel Machining
Machining 4142 steel can be challenging due to its hardness, especially in its heat-treated state. Use tools made of carbide or high-speed steel (HSS) for efficient cutting. The recommended cutting speed for 4142 steel varies between 35 to 70 m/min (115 to 230 ft/min), depending on the steel’s hardness level.
4142 Steel Welding
Welding 4142 steel requires careful management of heat to prevent cracking or distortion. The process generally follows these steps:
- Preheating: The steel should be preheated to 150 to 200°C (300 to 400°F), particularly for thicker sections, to minimize thermal shock and cracking risks.
- Welding Methods: TIG and MIG welding are the best methods for welding 4142 steel, allowing for precise control over the weld pool. While stick welding is feasible, it requires more attention to detail and skill.
- Post-Weld Heat Treatment: To relieve stresses and reduce the risk of cracking, the welded component should undergo post-weld tempering at 450 to 650°C (850 to 1,200°F).
SteelPro Group provides reliable welding services for 4142 steel, ensuring high-strength and durable welds for demanding applications.
4142 Alloy Steel Key Characteristics
Advantages
- High strength and toughness
- Excellent wear and fatigue resistance
- Good heat treatment flexibility
- Improved corrosion resistance due to chromium content
Disadvantages
- Higher cost compared to carbon steel
- Difficult to machine in the hardened state
- Limited corrosion resistance compared to stainless steel
- Requires preheating and post-weld treatment for welding
4140 vs 4142 Steel
4140 and 4142 steel are both medium-carbon alloy steels. For components that demand exceptional durability and resistance to wear, 4140 steel is the superior choice. For cost-sensitive applications where machinability is a priority, 4142 steel offers a more affordable solution.
4140 steel, containing elevated levels of chromium and molybdenum, provides enhanced hardenability, durability, and strength, making it perfect for demanding applications such as gears and crankshafts. On the other hand, 4142 steel, which contains lower levels of these elements, provides good strength but has reduced wear resistance. This makes it more appropriate for components that are less stress-intensive, like hydraulic pistons and axles.
In terms of machinability, 4142 steel is easier to work with, allowing for quicker production and lower machining costs. 4140 steel, while offering better performance in high-stress environments, is harder to machine
4142 Steel Custom Solutions and Final Processing
SteelPro Group’s commitment to quality and precision ensures that whether you need 4142 steel for forging, heat treatment, or custom machining, you’ll receive top-notch material tailored to your needs. Trust us for your next project—our expertise in 4142 steel guarantees reliability and performance, every time.
