AISI 4142 (UNS G41420) Alloy Forging Material Overview
Established in 1997, Jiangsu Liangyi is a professional ISO 9001:2015 certified China OEM manufacturer and supplier of AISI 4142 (also universally known as SAE 4142, UNS G41420, and Alloy 4142) open die forging parts and seamless rolled steel forged rings. With 27+ years of professional forging experience, we have become a trusted long-term supplier for industrial customers in more than 50 countries across North America, Europe, the Middle East, Southeast Asia, Australia, and South America.
As an industry-standard medium-carbon chromium-molybdenum alloy steel, AISI 4142 has excellent tensile strength, hardenability, great impact toughness, and high wear resistance after precision quenching and tempering. So that it is the best choice material for heavy-duty, high-torque, and high-stress industrial applications that require long-term reliable performance in harsh working environments.
We provide full end-to-end custom manufacturing from steel melting, open die forging, precision heat treatment, CNC machining to final quality inspection. All our AISI 4142 forgings fully meet international standards including ASTM, SAE, DIN, EN, JIS, and API 6A, with complete Mill Test Certificate (MTC) EN 10204 3.1/3.2 available for every order.
⚡ AISI 4142 Key Specifications at a Glance
Need custom AISI 4142 forging parts manufactured to your exact drawings? Contact us today for a free, no-obligation detailed quotation.
Custom AISI 4142 Forged Parts & Components We Manufacture
We support full OEM/ODM custom manufacturing of AISI 4142 forged parts based on your official engineering drawings, material specifications and performance requirements. Our main product range covers all common industrial forging forms for global projects, including but not limited to:
AISI 4142 Forged Bars & Rods
We supply precision forged AISI 4142 steel bars in multiple custom specifications, including round bars, square bars, flat bars, rectangular bars, step bars and fully custom rods. Our forged bars are strictly processed to ensure uniform grain structure and stable mechanical properties, fully suitable for subsequent precision machining, case hardening and other secondary processing. They are widely used in heavy machinery, hydraulic cylinders, structural components, and industrial shaft manufacturing.
SAE 4142 Seamless Rolled Rings & Forged Rings
Our SAE 4142 seamless rolled rings and forged rings are manufactured with our advanced 1–5 meter CNC seamless rolling machines, supporting custom sizes from small-diameter precision rings to large-diameter heavy-duty rolled rings. They are widely used for bearing races, gear rims, industrial flanges, riding rings, slewing bearing races and other circular components, with excellent fatigue resistance and load-bearing performance for heavy industrial equipment.
UNS G41420 Forged Shafts & Gear Components
We manufacture custom UNS G41420 forged shafts and precision gear components, including gear shafts, pinion shafts, spindles, gear wheels, ring gears, eccentric shafts, crankshafts and rotor shafts. All products can be fully tailored to meet the strict dimensional tolerance, surface finish and heat treatment requirements of high-load transmission and rotating systems in various heavy industries worldwide.
Alloy 4142 Custom Forged Housings, Casings & Special Shapes
We also produce high-quality Alloy 4142 custom forged parts, including hubs, housings, shells, sleeves, bushes, casings, discs, plates, pipe tubes, barrels, valve bodies, and other complex special-shaped forgings. Our forging capacity supports single piece weight from 30 KGS to 30,000 KGS, fully meeting the needs of different custom industrial projects and special-shaped component requirements.
Looking for non-standard custom AISI 4142 forged components for your project? Send us your drawings now to get a customized forging solution.
Why Choose Jiangsu Liangyi for Your AISI 4142 Forging Project?
With over 27 years of professional forging experience, we have become a trusted long-term supplier for global industrial OEMs, EPC contractors and engineering companies. Following are our main competitive advantages for your AISI 4142 forging projects:
Full-Process One-Stop Service
We provide full range of service from steel melting, forging, heat treatment to precision CNC machining, with zero outsourcing. Full-process quality control guarantees the stability and consistency of every AISI 4142 forging, supporting custom solutions for the most complex engineering drawings.
Advanced Production & Inspection Equipment
Our factory is equipped with a 6,300-ton hydraulic forging press, 1–5 meter seamless rolling machines, full set of CNC machining centers, and professional NDT, chemical composition and mechanical property testing equipment. Learn more about our state-of-the-art production and inspection facilities.
Strict International Standard Compliance
All AISI 4142 forged parts strictly meet ASTM, SAE, DIN, EN, JIS and other international material standards. We provide complete MTC EN 10204 3.1 certificates and full inspection reports for each order as standard. EN 10204 3.2 and third-party inspection (SGS, BV, TUV) are available upon customer arrangement.
Rich Global Project Experience
We have supplied high-quality AISI 4142 forgings to customers in more than 50 countries, and we have rich project experience in oil & gas, mining, power generation, cement and other heavy industries. View our global project references and success stories.
Flexible Production Capacity
Our 80,000 m² factory has an annual manufacturing capacity of 120,000 tons. We produce parts with weight range from 30 KGS to 30,000 KGS, and we support both small batch for trial parts and large-volume mass production orders.
Comprehensive Material Coverage
In addition to AISI 4142, we also specialize in carbon steel, other alloy steel, stainless steel, nickel alloy, tool steel and other forging material grades. View our full forging material list for your multi-material project needs.
Global Industry Applications & Field-Proven Project Cases
AISI 4142 alloy forgings are widely used in global heavy industries that need high strength, long service life and reliable performance under extreme working conditions. Following are our main application scenarios and verified project cases for customers worldwide:
Sugar & Cement Processing Industry
Our AISI 4142 forged parts are widely applied in sugar mill and cement plant equipment across Southeast Asia, Europe and Africa, including gear shafts, pinion shafts, roller shafts, rotary kiln components, riding gear rings, industrial flanges, couplings and pull torque rods.
Mining & Heavy Construction Equipment
We provide high-strength SAE 4142 forgings for global mining and heavy construction equipment projects in Australia, South America and North America.These parts include crusher eccentric shafts, gyratory crusher spindles, conveyor pulley shafts, excavator slewing bearing races, mine hoist system shafts, TBM cutter rings and crusher belt pulley wheels.
Wind & Hydro Power Generation Industry
AISI 4142 forged components are the best choice material for power generation equipment across Europe and North America, including wind turbine gearbox gear shafts, ring gears, hydro turbine shafts, gas and steam turbine rotors, generator shafts, labyrinth seal bushings and baffle rings.
Oil & Gas (Onshore & Offshore) Industry
We manufacture a full range of UNS G41420 forged parts for onshore and offshore oil and gas exploration and production projects in the Middle East, North America and Africa, including wellhead Christmas tree components, drilling tool gear shafts, mud pump parts, valve bodies, casing heads, tubing spools, blowout preventer (BOP) bodies, fracturing equipment parts and subsea equipment components, manufactured to API 6A material specifications upon request.
Transportation & General Industrial Machinery
Our SAE 4142 forgings are also widely used in locomotive transmission shafts, railway traction motor housings, truck ring gears and planetary gears, hydraulic honed cylinders, gearbox reducer components, crankshafts for gas compressors and pumps, cold mill coiler mandrel shafts, and flue gas desulfurization equipment atomizer shafts for global customers.
AISI 4142 Steel Manufacturing & Heat Treatment Specifications
Steel Making Process
The AISI 4142 steel used for our forgings is produced via advanced electric furnace process or basic oxygen process, with fully killed steel treatment and optional vacuum degassing treatment to ensure ultra-high material purity, consistent chemical composition and stable internal quality. All steel billets are subject to strict forging and rolling processing to refine the grain matrix, delete internal defects, and improve the comprehensive mechanical properties of the final parts.
Customizable Heat Treatment Process
We provide complete professional heat treatment services for AISI 4142 forging parts, which can be fully customized according to your required mechanical properties, hardness and application requirements. We can strictly control the strength, toughness and hardness of the material in heat treatment process to match your project needs. The standard heat treatment process is as follows:
- Hot Forging: Maximum initial forging temperature 1200°C (2192°F); minimum finish forging temperature 950°C (1742°F), to guarantee full forging penetration and consistent internal grain matrix.
- Annealing: 815°C – 850°C (1499°F – 1562°F), slow cooling in furnace, to reduce hardness (max 321 HB), improve machinability, relieve internal stress, and prepare for subsequent processing
- Normalizing: 870°C – 900°C (1598°F – 1652°F), cooling in air, to refine grain, improve matrix uniformity and comprehensive mechanical properties
- Quenching & Tempering (Hardening & Tempering): 820°C – 870°C (1508°F – 1598°F) oil quenching; tempering temperature ranges from 430°C to 700°C (806°F – 1292°F), flexibly adjusted according to your required strength, hardness and toughness matching requirements
Chemical Composition of UNS G41420 (AISI 4142) Alloy Steel
The chemical composition of our AISI 4142 forged parts strictly meet ASTM A29/A29M and SAE J404 international standards, with strict element control to guarantee stable material performance. Following is the specific element content range:
| Chemical Element | Standard Content Range (%) |
|---|---|
| Iron (Fe) | ≥ 96.725 |
| Chromium (Cr) | 0.80 – 1.10 |
| Manganese (Mn) | 0.75 – 1.10 |
| Carbon (C) | 0.40 – 0.45 |
| Silicon (Si) | 0.15 – 0.30 |
| Molybdenum (Mo) | 0.15 – 0.25 |
| Sulfur (S) | ≤ 0.040 |
| Phosphorus (P) | ≤ 0.035 |
Mechanical Properties of AISI 4142 Forged Raw Material
The typical mechanical properties of our AISI 4142 forged raw material (annealed state) are listed below. We can also fully customize the mechanical properties through different heat treatment processes (such as quenching and tempering) to meet the specific performance requirements of your application:
| Mechanical Property | Typical Standard Value (Annealed State) |
|---|---|
| Tensile Strength | 125,000 psi (862 MPa) |
| Yield Strength (0.2% Offset) | 105,000 psi (724 MPa) |
| Elongation | 16% |
| Reduction of Area | 50% |
| Maximum Hardness (Annealed) | 321 HB |
| Hardness Range (Quenched & Tempered) | 28 – 55 HRC (customizable) |
AISI 4142 vs 4140 vs 4130 vs 4340 — Grade Comparison
Choosing the right chromium-molybdenum alloy steel grade for your forging project depends on the required balance of strength, hardenability, toughness and cost. The table below compares AISI 4142 with the most commonly specified alternative grades to help you make an informed choice:
| Property / Feature | AISI 4142 ★ | AISI 4140 | AISI 4130 | AISI 4340 |
|---|---|---|---|---|
| UNS Designation | G41420 | G41400 | G41300 | G43400 |
| Carbon Content (%) | 0.40 – 0.45 | 0.38 – 0.43 | 0.28 – 0.33 | 0.38 – 0.43 |
| Chromium Content (%) | 0.80 – 1.10 | 0.80 – 1.10 | 0.80 – 1.10 | 0.70 – 0.90 |
| Molybdenum Content (%) | 0.15 – 0.25 | 0.15 – 0.25 | 0.15 – 0.25 | 0.20 – 0.30 |
| Nickel Content (%) | — | — | — | 1.65 – 2.00 |
| Tensile Strength (Annealed) | 125,000 psi | 148,000 psi* | 97,000 psi* | 108,000 psi* |
| Relative Hardenability | High | High | Moderate | Very High |
| Relative Strength | High | High | Moderate | Very High |
| Relative Toughness | Good | Very Good | Very Good | Excellent |
| Wear Resistance (after HT) | Very Good | Good | Moderate | Good |
| Relative Cost | Low–Medium | Low–Medium | Low | Medium–High |
| Typical Forging Applications | Gear shafts, pinion shafts, crusher eccentric shafts, valve bodies, rolling mill rolls | Axle shafts, bolts, couplings, general machinery | Pressure vessels, tubing, thin-wall components | Aircraft parts, heavy-duty gears, high-impact components |
* Typical values for normalized/annealed condition; actual values depend on section size and specific heat treatment. AISI 4142 is recommended when maximum wear resistance and hardness at moderate cost are the priority. Contact us if you need guidance on grade choice for your specific application.
Not sure which grade is right for your application? Email our engineers with your requirements for a free technical recommendation.
Quality Assurance & Full Test Certification
All our AISI 4142 forging parts are subject to strict full-process quality inspection from raw material incoming to finished product delivery, to make sure that every product meets your requirements and international standards. We have a professional quality control team and complete testing equipment to implement full-process traceability management for each order. The complete official test certificate for finished forged steel parts will include the following full details:
- Heat number and melting type of the raw steel
- Full dimension test report with actual measured data
- Detailed records of the complete heat treatment cycle applied
- Full chemical analysis results (including tramp elements)
- Complete mechanical test results (including hardness test, with all individual values reported)
- Nondestructive testing results (ultrasonic test, magnetic particle test, etc.)
- Surface crack examination results
- Visual inspection and dimensional verification confirmation
- Results of any additional tests specified in your drawings or order requirements
Frequently Asked Questions About AISI 4142 Forgings
AISI 4142 and SAE 4142 refer to the exact same alloy steel grade. AISI (American Iron and Steel Institute) and SAE (Society of Automotive Engineers) are two different standard-setting organizations that jointly developed this grade specification, so the two names are completely interchangeable in industrial applications. It is also designated as UNS G41420 in the Unified Numbering System.
The main difference is the carbon composition: AISI 4142 has a carbon range of 0.40-0.45% as opposed to AISI 4140, which has a carbon range of 0.38-0.43%. This gives the AISI 4142 a slightly higher tensile strength, hardness and wear resistance after heat treatment. The 4140 has slightly better ductility. Both are common in heavy duty forging applications and we can produce custom forgings in both grades.
AISI 4142 has a perfect balance of high tensile strength, excellent hardenability, good impact toughness and high wear resistance after proper heat treatment. It has good forgeability, can be easily forged into complicated custom shapes, and is suitable for different heavy-duty applications requiring high load-bearing capacity and fatigue resistance. It is also less expensive than high-alloy grades, while meeting most industrial performance requirements.
Our AISI 4142 forged parts strictly meet ASTM A29/A29M, SAE J404, and other international material standards. We can also meet the requirements of DIN, EN, JIS, and API 6A standards according to your project needs, and provide corresponding EN 10204 3.1/3.2 mill test certificates for all orders.
We can produce AISI 4142 forgings with weight range from 30 KGS to 30,000 KGS per single piece.For forged bars, the maximum diameter is up to 1200 mm and maximum length is up to 16,000 mm.For seamless rolled rings, the maximum outer diameter is up to 5000 mm.Fully custom sizes are available based on your official drawings and specifications
Yes, we provide a full range of process services including rough machining, semi-finish machining and precision finish machining according to your drawings. We can deliver finished AISI 4142 parts that can be directly assembled, saving your procurement, transportation and secondary processing costs.
The hardness of AISI 4142 is fully customizable through our precision heat treatment process. In the annealed state, the maximum hardness is 321 HB. After quenching and tempering, we can get a hardness range of 28 HRC to 55 HRC, which can be customized based on your specific strength, toughness and wear resistance requirements for your application.
The real lead time depends on the drawings, quantity, and processing requirements. For normal forged bars and simple parts, the lead time is 7–15 working days.For complex custom forgings that need machining and heat treatment, the lead time is 20–30 working days.We can also speed up production for urgent orders.
Yes, we do small batch for trial parts of AISI 4142 forging. We realize that many customers need to try out material performance and part fit before mass production, and we can offer flexible production solutions for both small batch trials and large-scale mass production orders.
We provide official Mill Test Certificate (MTC) EN 10204 3.1 for all AISI 4142 orders as standard. EN 10204 3.2 certificates — which require an independent third-party inspection body to witness testing — are also available when the customer arranges a qualified third-party inspector (such as SGS, BV, or TUV). All certificates include complete chemical composition, mechanical properties, heat treatment records, nondestructive testing results and dimension test data.
Request a Custom Quotation for Your AISI 4142 Forging Project Today
Jiangsu Liangyi has rich experience in manufacturing custom AISI 4142 (SAE 4142, UNS G41420) alloy forging parts for global OEMs, engineering companies and project contractors. Whether you need standard forged bars and rings, or complex custom-shaped forgings for specific industrial applications, we can provide you with reliable, high-quality and cost-effective solutions.
Welcome to send us your detailed drawings, material requirements, quantity and other specifications to get a quick and detailed quotation.
📧 Inquiry Email: sales@jnmtforgedparts.com
📞 Phone/WhatsApp: +86-13585067993 (Click to call or add WhatsApp directly)
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📍 Factory Address: Chengchang Industry Park, Jiangyin City, Jiangsu Province, China