Spherical Latrobe LSS™ 4140 Alloy Steel Powder (AISI 4140)

Latrobe LSS™ 4140 Alloy Steel Spherical Powder (AISI 4140) Product Information -:- For detailed product information, please contact sales. -: Latrobe LSS™ 4140 Alloy Steel Spherical Powder (AISI 4140) Synonyms -:- For detailed product information, please contact sales. -: -:- For detailed product information, please contact sales. -: Spherical Latrobe LSS™ 4140 Alloy Steel Powder (AISI 4140) characteristics -:- For detailed product information, please contact sales. -: Spherical Latrobe LSS™ 4140 Alloy Steel Powder (AISI 4140) Particle Size -:- For detailed product information, please contact sales. -: -:- -:- 0-15μm ,5-25μm, 15-45μm, 15-53μm,20-63um, 45-75μm, 45-105μm, 45-150μm ,75-150μm. (Various granularities can be customized according to customer requirements) -:- For detailed product information, please contact sales. -:

Spherical Latrobe LSS™ 4140 Alloy Steel Powder (AISI 4140) Applicable processes -:- For detailed product information, please contact sales. -: Laser/electron beam additive manufacturing (SLM/EBM, 3D printing) Direct laser deposition (DLD) Used in thermal spray (TSA) Powder hot isostatic pressing (HIP) Metal injection molding (MIM) Powder metallurgy (PM) Laser cladding (LC), etc. -:- For detailed product information, please contact sales. -: Spherical Latrobe LSS™ 4140 Alloy Steel Powder (AISI 4140) Chemical Composition -:- For detailed product information, please contact sales. -: -:- For detailed product information, please contact sales. -: Latrobe LSS™ 4140 Alloy Steel (AISI 4140) Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: Latrobe LSS™ 4140 Alloy Steel (AISI 4140 / ASTM A29)** **Latrobe LSS™ 4140** is a premier-grade, **chromium-molybdenum (Cr-Mo) alloy steel** renowned for its exceptional combination of high strength, good toughness, and excellent hardenability. As one of the most versatile and widely used medium-carbon alloy steels in industry, AISI 4140 offers outstanding performance across a broad range of mechanical applications through proper heat treatment. Its balanced chemistry provides deep hardening characteristics, making it suitable for both small components and large cross-sections requiring uniform properties. The key advantage of LSS™ 4140 lies in its ability to achieve **high tensile strength (up to 1,380 MPa / 200 ksi) while maintaining good ductility and impact resistance** through quenching and tempering treatments. This versatile steel serves as the benchmark for general-purpose high-strength components in virtually every manufacturing sector, from automotive to aerospace and heavy machinery. --- ## **1. Chemical Composition** Latrobe LSS™ 4140 features a precise chromium-molybdenum alloy system optimized for strength and hardenability: | Element | Content (%) | Function | | :--- | :--- | :--- | | Carbon (C) | 0.38 - 0.43 | Provides core strength and hardness | | Chromium (Cr) | 0.80 - 1.10 | Enhances hardenability, wear and corrosion resistance | | Molybdenum (Mo) | 0.15 - 0.25 | Increases hardenability, strength, and creep resistance | | Manganese (Mn) | 0.75 - 1.00 | Improves hardenability and strength | | Silicon (Si) | 0.15 - 0.30 | Increases strength and oxidation resistance | | Phosphorus (P) | ≤ 0.035 | Residual element (controlled) | | Sulfur (S) | ≤ 0.040 | Residual element (controlled) | | **Balance** | Iron (Fe) | | *(Composition conforms to AISI 4140 and ASTM A29 specifications)* --- ## **2. Physical & Mechanical Properties** ### **As-Annealed/Normalized Condition:** - **Hardness:** 197 - 229 HB (Brinell) - **Tensile Strength:** 655 MPa (95 ksi) - **Yield Strength:** 415 MPa (60 ksi) - **Elongation:** 25.7% - **Reduction of Area:** 56.9% - **Machinability:** 65% (relative to 1212 steel) - **Density:** 7.85 g/cm³ (0.284 lb/in³) - **Modulus of Elasticity:** 205 GPa (29.7 × 10⁶ psi) ### **Heat Treatment Characteristics:** - **Hardenability Index (DI):** 3.4 inch (ideal Jominy distance) - **Critical Cooling Rate:** Moderate - **Forging Temperature:** 1150°C - 900°C (2100°F - 1650°F) - **Annealing Temperature:** 830°C - 860°C (1525°F - 1580°F) - **Normalizing Temperature:** 870°C - 900°C (1600°F - 1650°F) ### **Quenched & Tempered Properties:** *(Oil quenched from 845°C/1550°F)* | Temper Temperature | Hardness (HRC) | Tensile Strength | Yield Strength | % Elongation | % RA | Impact Energy (Charpy V) | | :--- | :--- | :--- | :--- | :--- | :--- | :--- | | **205°C (400°F)** | 52-56 | 1790 MPa (260 ksi) | 1655 MPa (240 ksi) | 11% | 35% | 20 J (15 ft-lb) | | **425°C (800°F)** | 42-46 | 1310 MPa (190 ksi) | 1170 MPa (170 ksi) | 16% | 50% | 41 J (30 ft-lb) | | **540°C (1000°F)** | 35-39 | 1035 MPa (150 ksi) | 930 MPa (135 ksi) | 19% | 58% | 54 J (40 ft-lb) | | **650°C (1200°F)** | 25-29 | 690 MPa (100 ksi) | 585 MPa (85 ksi) | 23% | 65% | 81 J (60 ft-lb) | --- ## **3. International Standards & Cross-Reference** | Country/Region | Standard | Designation | Equivalent/Specification | | :--- | :--- | :--- | :--- | | **United States** | AISI/SAE | 4140 | G41400 | | | ASTM | A29 | 4140 | | | UNS | G41400 | | | **Germany** | DIN | 1.7225 | 42CrMo4 | | **European Union** | EN | 1.7225 | 42CrMo4 | | **Japan** | JIS | G4105 | SCM440 | | **United Kingdom** | BS | 708A37 | 709M40 | | **France** | AFNOR | 42CD4 | | | **Italy** | UNI | 38CrMo4 | | | **Sweden** | SS | 2244 | | | **China** | GB | 42CrMo | | | **International** | ISO | 683-1 | 42CrMo4 | --- ## **4. Product Applications** ### **Automotive & Transportation:** - **Axle Shafts and Drive Shafts** - **Crankshafts and Connecting Rods** - **Gears, Sprockets, and Sleeves** - **Suspension Components and Steering Parts** - **Wheel Spindles and Hubs** ### **Aerospace & Defense:** - **Aircraft Landing Gear Components** - **Engine Mounts and Brackets** - **Missile and Rocket Components** - **Helicopter Rotor Parts** ### **Oil & Gas Industry:** - **Drill Collars and Tool Joints** - **Valve Bodies and Trim** - **Pump Shafts and Rotors** - **Wellhead Components** ### **General Machinery:** - **Hydraulic Cylinder Rods and Pistons** - **Machine Tool Spindles and Arbors** - **Die Blocks and Molds** - **Bolts, Studs, and High-Strength Fasteners** - **Rolls and Mill Equipment** ### **Construction & Mining:** - **Excavator and Dozer Components** - **Crusher Parts and Hammer Pins** - **Mining Drill Bits and Rods** - **Crane and Hoist Components** --- ## **5. Processing Guidelines** ### **Machining (Annealed/Normalized State):** - **Turning Speed:** 50-70 m/min (165-230 ft/min) with carbide tools - **Feed Rate:** 0.25-0.40 mm/rev (0.010-0.015 in/rev) - **Depth of Cut:** Up to 5mm (0.200") roughing - **Tool Geometry:** Positive rake angles recommended - **Coolant:** Required for optimal tool life and surface finish ### **Heat Treatment Options:** **1. Annealing:** - Temperature: 830°C - 860°C (1525°F - 1580°F) - Cooling: Furnace cool to 600°C (1110°F), then air cool - Result: 197-229 HB for optimum machinability **2. Normalizing:** - Temperature: 870°C - 900°C (1600°F - 1650°F) - Cooling: Air cool - Result: Improved machinability and grain refinement **3. Quenching & Tempering:** - Austenitizing: 830°C - 860°C (1525°F - 1580°F) for 30 min/inch - Quenching: Oil (preferred) or water for smaller sections - Tempering: 205°C - 650°C (400°F - 1200°F) for 1-2 hours per inch - Cooling: Air cool after tempering **4. Induction Hardening:** - Surface Hardness: 55-60 HRC achievable - Case Depth: 1-6mm (0.040-0.250") typical - Core Properties: Maintained for toughness ### **Welding Considerations:** - **Weldability:** Fair (requires precautions) - **Preheat:** 150°C - 315°C (300°F - 600°F) depending on section size - **Post-Weld Heat Treatment:** Required for critical applications - **Filler Metals:** AWS E11018, E12018 or equivalent - **Technique:** Low hydrogen process required ### **Surface Treatments:** - **Nitriding:** Excellent response (500-700 HV typical) - **Carburizing:** Can be carburized for case hardening - **Hard Chrome Plating:** Good adhesion - **Phosphating/Parkerizing:** For corrosion resistance --- ## **6. Technical Advantages** ### **Compared to Similar Grades:** | Property | 4140 vs. 4340 | 4140 vs. 4150 | 4140 vs. 1045 | | :--- | :--- | :--- | :--- | | **Strength** | Slightly lower | Lower carbon version | Significantly higher | | **Toughness** | Slightly lower | Similar | Much better | | **Hardenability** | Lower | Similar | Much higher | | **Cost** | Lower | Similar | Higher | | **Weldability** | Better | Similar | Better | | **Machinability** | Better | Better | Lower | ### **Unique Benefits of LSS™ 4140:** 1. **Excellent Strength-to-Weight Ratio** 2. **Good Fatigue Resistance** 3. **Relatively Low Cost for Performance** 4. **Wide Availability in Various Forms** 5. **Predictable Heat Treatment Response** 6. **Good Combination of Wear and Impact Resistance** --- ## **7. Available Forms & Specifications** ### **Standard Product Forms:** - **Round Bars:** 5mm to 600mm diameter (0.1875" to 24") - **Hexagon Bars:** 5mm to 100mm across flats - **Square Bars:** 5mm to 150mm - **Flat Bars:** 3mm to 300mm thick, various widths - **Billets & Blooms:** For forging - **Forged Shapes:** Custom configurations - **Plate:** Up to 300mm thick - **Tube & Pipe:** Various specifications ### **Surface Conditions:** - **Hot Rolled (HR):** Black surface, mill scale - **Cold Finished (CF):** Turned, ground, or polished - **Rough Turned:** For machining stock - **Precision Ground:** Close tolerance applications ### **Quality Designations:** - **Standard Quality:** For general applications - **Special Quality:** Enhanced cleanliness, reduced segregation - **Aircraft Quality:** Per AMS, MIL, or other aerospace specs - **Ultrasonic Tested:** For critical applications --- ## **8. Specialized Variants** ### **Modified 4140 Grades:** - **4140 HT:** Higher toughness variant - **4140 Mod.:** Enhanced hardenability version - **4140 ESR:** Electro-slag remelted for improved purity - **4140 VAR:** Vacuum arc remelted for ultra-clean steel ### **Heat-Treated Conditions:** - **Annealed:** For maximum machinability - **Normalized:** For improved properties before final heat treatment - **Quenched & Tempered:** To specified hardness/strength levels - **Pre-hardened:** Typically 28-32 HRC for mold applications --- **Technical Summary:** Latrobe LSS™ 4140 represents the **quintessential workhorse alloy steel** – offering an outstanding balance of strength, toughness, hardenability, and cost-effectiveness that has made it the most widely specified medium-carbon alloy steel worldwide. Its versatility across heat treatment conditions (from highly machinable annealed states to ultra-high strength quenched and tempered conditions) makes it suitable for an exceptionally broad range of applications. While specialized grades may exceed it in specific properties, 4140 remains the benchmark for general high-strength applications due to its proven performance, predictable behavior, and excellent value proposition. **Industry Significance:** Approximately 70% of all chromium-molybdenum alloy steel used in industry is based on the 4140 composition or its close variants, demonstrating its fundamental importance in mechanical engineering and manufacturing. **Processing Note:** The full potential of 4140 is realized through proper heat treatment. Consultation with metallurgical experts is recommended for critical applications to optimize the heat treatment cycle for specific service requirements. **Disclaimer:** The mechanical properties listed are typical and can vary based on exact chemistry, processing history, and heat treatment parameters. For critical applications, always consult Latrobe's current technical data sheets and conduct testing under actual service conditions. Proper heat treatment by qualified personnel is essential for achieving optimal performance. -:- For detailed product information, please contact sales. -: Latrobe LSS™ 4140 Alloy Steel (AISI 4140) Specification Dimensions Size： Diameter 20-1000 mm Length <7207 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: Latrobe LSS™ 4140 Alloy Steel (AISI 4140) Properties -:- For detailed product information, please contact sales. -:

Spherical Latrobe LSS™ 4140 Alloy Steel Powder (AISI 4140) Particle Size Description -:- For detailed product information, please contact sales. -: Applications of Spherical Latrobe LSS™ 4140 Alloy Steel Powder (AISI 4140) -:- For detailed product information, please contact sales. -: -:- For detailed product information, please contact sales. -: Applications of Latrobe LSS™ 4140 Alloy Steel Spherical Powder (AISI 4140) -:- For detailed product information, please contact sales. -: Chemical Identifiers Latrobe LSS™ 4140 Alloy Steel Spherical Powder (AISI 4140) -:- For detailed product information, please contact sales. -:

Packing of Latrobe LSS™ 4140 Alloy Steel Spherical Powder (AISI 4140) -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Spherical Powder drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 3678 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition