AISI 4620 Steel, normalized

AISI 4620 Steel, normalized, 13 mm (0.5 in.) round Product Information -:- For detailed product information, please contact sales. -: AISI 4620 Steel, normalized, 13 mm (0.5 in.) round Synonyms -:- For detailed product information, please contact sales. -:

AISI 4620 Steel, normalized, 13 mm (0.5 in.) round Product Information -:- For detailed product information, please contact sales. -: # **Technical Specification: AISI 4620 Steel, Normalized Condition, 13 mm (0.5 in.) Round Bar** ## **1. PRODUCT OVERVIEW** AISI 4620 steel supplied as **13 mm (0.5 inch) diameter round bars in the normalized condition** represents a premium low-carbon nickel-molybdenum alloy steel optimized for precision manufacturing and consistent response to subsequent heat treatment. Normalization refines the grain structure and homogenizes the microstructure, resulting in a **fine, uniform ferrite-pearlite matrix** that offers an optimal balance of machinability, strength, and dimensional predictability. The 13 mm diameter is ideal for small to medium-sized precision components, providing excellent through-section uniformity and reliable performance as a high-quality stock material for parts destined for case hardening processes like carburizing. ## **2. PRODUCT SPECIFICATIONS & STANDARDS** | **Parameter** | **Specification** | **Governing Standards** | |---------------|-------------------|-------------------------| | **Material Designation** | AISI 4620 / SAE 4620 | SAE J404, SAE J412 | | **UNS Number** | G46200 | ASTM A29 | | **International Equivalents** | DIN 1.6523, 20NiCrMo2-2 | ISO 683-11:2016 | | **Product Form** | Hot-rolled or cold-finished round bar | ASTM A29/A29M | | **Diameter** | 13.0 mm ± 0.2 mm (0.512 in. ± 0.008 in.) | Precision tolerance | | **Condition** | Normalized (Air-cooled from austenitizing temperature) | — | | **Normalizing Temperature** | ~900°C (1650°F) typical | — | | **Typical Hardness** | 179-217 HB (91-99 HRB) | ASTM E10/E18 | | **Straightness** | ≤ 1.0 mm per 300 mm (0.04 in./ft) | Standard commercial | | **Surface Finish (as-supplied)** | Hot-rolled & descaled or turned | Optional cold-drawn/polished available | ## **3. CHEMICAL COMPOSITION** | **Element** | **Minimum (%)** | **Maximum (%)** | **Typical (%)** | **Function in Normalized State** | |-------------|-----------------|-----------------|-----------------|---------------------------------| | **Carbon (C)** | 0.17 | 0.22 | 0.19 | Provides base strength; optimal for machining and subsequent case hardening. | | **Manganese (Mn)** | 0.45 | 0.65 | 0.55 | Enhances hardenability, improves strength through solid solution strengthening. | | **Phosphorus (P)** | — | 0.035 | 0.015 | Residual element (controlled). | | **Sulfur (S)** | — | 0.040 | 0.025 | Improves machinability through chip-breaking effect. | | **Silicon (Si)** | 0.15 | 0.35 | 0.25 | Deoxidizer; provides solid solution strengthening. | | **Nickel (Ni)** | 1.65 | 2.00 | 1.80 | **Critical element:** Provides inherent toughness and improves hardenability. Ensures exceptional core properties after final heat treatment. | | **Molybdenum (Mo)** | 0.20 | 0.30 | 0.25 | Refines grain structure, enhances hardenability, prevents temper embrittlement. | | **Iron (Fe)** | Balance | Balance | Balance | Matrix. | **Key Characteristics for 13 mm Normalized Rounds:** * **Carbon Equivalent (CE):** ~0.40-0.45 * **Hardenability Index:** Good; suitable for consistent through-hardening in this diameter * **Section Sensitivity:** Minimal due to small diameter, ensuring uniform transformation during normalization * **Prior Austenite Grain Size:** ASTM 7-9 (fine-grained) ## **4. NORMALIZING PROCESS & MICROSTRUCTURE** ### **4.1 Normalizing Thermal Cycle** The material is heated to approximately 900°C (1650°F) – significantly above the Ac₃ temperature – held for sufficient time, then air-cooled in still air. **Resultant Microstructure (13 mm Section):** * **Matrix:** Fine, equiaxed ferrite grains with uniformly distributed pearlite colonies. * **Pearlite Content:** ~30-40% (finely dispersed). * **Grain Size:** ASTM 7-9 (refined structure). * **Key Advantages:** The fine grain structure provides better mechanical properties than the as-rolled condition and more consistent response to subsequent heat treatment than the annealed condition. The small diameter ensures rapid and uniform cooling, producing a homogeneous microstructure throughout the cross-section. ## **5. MECHANICAL PROPERTIES (NORMALIZED CONDITION)** | **Property** | **Value Range** | **Test Standard** | **Notes for 13 mm Round** | |--------------|-----------------|-------------------|---------------------------| | **Hardness** | 179-217 HB (91-99 HRB) | ASTM E10/E18 | Excellent uniformity (±10 HB typical). | | **Ultimate Tensile Strength** | 550-690 MPa (80-100 ksi) | ASTM E8/E8M | Longitudinal direction. | | **Yield Strength (0.2% offset)** | 345-485 MPa (50-70 ksi) | ASTM E8/E8M | | | **Elongation (in 50 mm)** | 22-28% | ASTM E8/E8M | Good ductility. | | **Reduction of Area** | 50-60% | ASTM E8/E8M | | | **Modulus of Elasticity** | 200-205 GPa (29,000-29,700 ksi) | ASTM E111 | | | **Charpy V-Notch Impact (20°C)** | 50-70 J (37-52 ft·lb) | ASTM E23 | **Excellent toughness** due to Ni content. | | **Fatigue Strength (Rotating Bending)** | ~280-320 MPa | Estimated, R=-1, 10⁷ cycles | Good for non-hardened state. | | **Machinability Rating** | 65-70% (vs. 1212 steel) | Industry Standard | Very good; better chip control than annealed. | ## **6. PHYSICAL PROPERTIES** | **Property** | **Value** | **Unit** | |--------------|-----------|----------| | Density | 7.85 | g/cm³ | | Thermal Conductivity (20°C) | 46.0 | W/m·K | | Specific Heat (20°C) | 475 | J/kg·K | | Mean CTE (20-100°C) | 12.3 × 10⁻⁶ | /K | | Electrical Resistivity (20°C) | 0.21 | μΩ·m | | Magnetic Properties | Ferromagnetic | — | ## **7. APPLICATIONS** AISI 4620 normalized 13 mm round bar serves as superior manufacturing stock for small, high-precision components that will undergo case hardening. It is particularly valued in automated, high-volume production environments. ### **7.1 Target Component Families** | **Industry** | **Typical Components Machined from This Stock** | |--------------|-------------------------------------------------| | **Automotive** | Small transmission gears, synchronizer rings, shift forks, fuel injection components, valve train parts, precision pins. | | **Aerospace** | Actuator components, linkage pins, small gear blanks, fastener blanks for high-strength bolts. | | **Industrial Machinery** | Precision shafts, small rollers, bushings, guide pins, sensor components. | | **Hydraulic/Pneumatic** | Valve spools, pump gears, piston rods (small diameter), connector parts. | | **Consumer Durables** | High-performance bicycle and motorcycle components, power tool gears. | ### **7.2 Advantages of Normalized 4620 in 13 mm Rounds** 1. **Consistent Machinability:** Provides stable cutting forces and predictable tool wear, ideal for CNC and multi-spindle automation. 2. **Superior Dimensional Stability:** More stable during machining than annealed material, with less tendency for distortion. 3. **Better Surface Finish:** The finer microstructure often yields a better machined surface finish compared to annealed stock. 4. **Optimized for Subsequent HT:** The refined, homogeneous structure ensures very consistent case depth and core properties after carburizing. 5. **Good Balance of Properties:** Offers higher strength than annealed condition while maintaining very good machinability. ## **8. PROCESSING CHARACTERISTICS** ### **8.1 Machinability** | **Operation** | **Recommended Parameters** | **Tooling Suggestions** | |---------------|----------------------------|-------------------------| | **Turning** | Vc = 140-180 m/min, f = 0.20-0.35 mm/rev | Coated carbide (TiCN/TiAlN). | | **Drilling** | Vc = 25-35 m/min, f = 0.15-0.25 mm/rev | HSS-Co or carbide drills. | | **Milling** | Vc = 120-160 m/min, fz = 0.10-0.20 mm/tooth | Carbide end mills. | | **Threading/Tapping** | 65-75% of drilling speed | TiN-coated HSS tools. | ### **8.2 Subsequent Heat Treatment (Typical Path)** * **Process:** Carburizing at 900-925°C → Direct Oil Quench or Reheat & Quench → Temper (150-200°C). * **Expected Final Properties:** * **Surface Hardness:** 58-63 HRC. * **Effective Case Depth:** Typically 0.3-1.0 mm for small components. * **Core Hardness:** 35-40 HRC (exceptionally tough due to Ni). * **Note:** All major machining operations should be completed in this normalized state. ### **8.3 Weldability** * **Rating:** Good (with standard precautions). * **Procedure:** Preheating (100-150°C) recommended. Use low-hydrogen electrodes (AWS E8018-C3). For best results, weld in normalized condition and follow with full heat treatment (including carburizing) if required. ## **9. INTERNATIONAL STANDARDS & EQUIVALENTS** | **Standard** | **Designation / Approach** | **Notes** | |--------------|----------------------------|-----------| | **SAE (USA)** | 4620 | Base material standard. | | **ASTM (USA)** | A29/A29M (Grade 4620) | Specify condition "Normalized". | | **DIN (Germany)** | 1.6523 / 20NiCrMo2-2 | Closest common equivalent. | | **ISO** | ISO 683-11:2016 | Designation for case-hardening steels. | | **JIS (Japan)** | SNCM220 | Common Japanese equivalent. | ## **10. QUALITY ASSURANCE** Standard supply typically includes: * **Mill Test Certificate:** Confirming chemical composition to AISI 4620. * **Hardness Test Report:** Brinell or Rockwell B scale. * **Dimensional Certification.** Optional tests for critical applications: * **Microstructure Evaluation:** Verification of normalized structure (fine ferrite-pearlite). * **Grain Size Measurement:** Per ASTM E112. * **Ultrasonic Testing:** For internal quality assurance. ## **11. COMPARATIVE GUIDANCE** | **Aspect** | **Normalized 13 mm Round** | **Annealed 13 mm Round** | **Application Recommendation** | |------------|----------------------------|--------------------------|--------------------------------| | **Hardness** | Higher (179-217 HB) | Lower (149-179 HB) | Normalized for better strength in pre-hardened state. | | **Machinability** | Very Good | Excellent | Annealed for most aggressive/complex machining. | | **Dimensional Stability** | Better | Good | Normalized preferred for precision components. | | **Subsequent HT Response** | More Consistent | Consistent | Both good; normalized has slight edge. | | **Surface Finish (as-machined)** | Often Better | Good | Normalized can produce finer finishes. | ## **12. SUMMARY** **AISI 4620 in 13 mm normalized round bar is the preferred engineering choice for manufacturing high-precision, case-hardened components in small to medium sizes.** It delivers an optimal combination of consistent machinability, good strength, excellent dimensional stability, and predictable response to carburizing. The fine-grained normalized structure ensures reliable performance in high-volume production environments, while the nickel-molybdenum chemistry guarantees that finished parts will exhibit outstanding core toughness beneath a wear-resistant case. This material represents a balanced, high-performance starting point for critical components across automotive, aerospace, and precision engineering sectors. --- **Disclaimer:** The properties listed are typical for commercially normalized material. Actual values may vary based on the specific normalizing parameters and mill practices. For design-critical applications, validation testing with production material is recommended. -:- For detailed product information, please contact sales. -: AISI 4620 Steel, normalized, 13 mm (0.5 in.) round Specification Dimensions Size： Diameter 20-1000 mm Length <5639 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. -: AISI 4620 Steel, normalized, 13 mm (0.5 in.) round Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 4620 Steel, normalized, 13 mm (0.5 in.) round -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 4620 Steel, normalized, 13 mm (0.5 in.) round -:- For detailed product information, please contact sales. -:

Packing of AISI 4620 Steel, normalized, 13 mm (0.5 in.) round -:- 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 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 2110 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