AISI 51B60 Steel, normalized

AISI 51B60 Steel, normalized, 13 mm (0.5 in.) round Product Information -:- For detailed product information, please contact sales. -: AISI 51B60 Steel, normalized, 13 mm (0.5 in.) round Synonyms -:- For detailed product information, please contact sales. -:

AISI 51B60 Steel, normalized, 13 mm (0.5 in.) round Product Information -:- For detailed product information, please contact sales. -: ### **Product Datasheet: AISI 51B60 Steel, Normalized Condition, 13 mm (0.5 in.) Round Bar** --- #### **1. Product Overview** This product is a **13 mm (0.5 inch) diameter round bar** of **AISI 51B60 boron-treated alloy steel**, supplied in the **normalized condition**. The **"B" suffix** indicates the intentional addition of **Boron**, a potent trace element that significantly enhances hardenability at minimal cost. In the normalized state, this bar delivers a refined, uniform microstructure with optimized strength and machinability, while the boron addition provides **superior and more economical depth of hardening** compared to a standard 5160 steel. This makes it an efficient, high-performance material for precision components that require reliable through-hardening and consistent manufacturing properties. #### **2. Material & Condition Concept: Boron-Enhanced Normalized Steel** - **Base Material (AISI 51B60):** A member of the **"51Bxx" series**, where "51" denotes ~1% chromium, "60" denotes ~0.60% carbon, and **"B" signifies boron treatment**. A minute boron addition (0.0005-0.003%) dramatically improves hardenability by segregating to austenite grain boundaries, delaying the formation of soft transformation products like ferrite and pearlite. - **Normalized Condition:** The steel has been reheated to approximately 870-900°C (1600-1650°F) and uniformly air-cooled. This process: 1. **Refines the Microstructure:** Produces a fine, homogeneous mixture of ferrite and pearlite, ideal for machining and as a precursor to hardening. 2. **Activates Boron Efficacy:** Ensures a uniform, fine-grained austenitic structure prior to cooling, which is optimal for boron to exert its full hardenability-enhancing effect during the final quench. 3. **Provides Optimal Pre-Hardening State:** Offers the best balance of strength for dimensional stability during machining and a consistent starting condition for final heat treatment. #### **3. International Standard & Specifications** - **Primary Standard:** **SAE J404** / **SAE J770** (Hardenability Ranges for Boron Steels) for the 51B60 composition. - **Condition Standard:** **ASTM A29/A29M** (Standard Specification for Steel Bars, normalized condition). - **UNS Designation:** **G51601** - **"H" Grade Variant:** **51B60H** is available (per ASTM A304) for applications requiring guaranteed hardenability bands. - **European Approximate Equivalent:** **1.5532 (55B2)** according to EN 10083-3 is a similar boron-treated steel in normalized condition. - **Japanese Equivalent:** No direct JIS equivalent for this boron steel series. #### **4. Chemical Composition (% by Weight, per SAE Specifications for Boron Steels)** | Element | Content Range (%) | Key Role in Normalized "B" Steel | | :--- | :--- | :--- | | **Carbon (C)** | **0.56 – 0.64** | Primary hardening element; forms fine pearlite in normalized state. | | **Manganese (Mn)** | **0.75 – 1.00** | Enhances hardenability and solid solution strength. | | **Phosphorus (P)** | **≤ 0.035** | Impurity; kept low. | | **Sulfur (S)** | **≤ 0.040** | Impurity; kept low. | | **Silicon (Si)** | **0.15 – 0.30** | Deoxidizer; strengthens ferrite matrix. | | **Chromium (Cr)** | **0.70 – 0.90** | Improves hardenability, wear resistance, and refines microstructure. | | **Boron (B)** | **0.0005 – 0.003*** | **Potent Hardenability Multiplier.** Effective in trace amounts. | | **Titanium (Ti)** | **(Often present)** | **Boron Protectant** (~0.02-0.05%) to ensure boron remains active. | | **Iron (Fe)** | **Balance** | Base metal. | #### **5. Physical & Mechanical Properties (As-Normalized, 13mm Round)** **A. Physical Properties:** - **Diameter:** 13.0 mm ± 0.25 mm (Precision tolerance typical for cold-drawn or turned normalized bars). - **Straightness:** Excellent straightness, suitable for automated feeding. - **Surface Condition:** Typically supplied with a clean, descaled surface (pickled & oiled) or precision turned for critical applications. - **Density:** 7.85 g/cm³ **B. Mechanical Properties (Normalized State):** - **Hardness (Brinell):** **229 – 285 HBW** (Approx. **100 – 108 HRB / 22-30 HRC**) - **Tensile Strength:** **770 – 930 MPa** (112 – 135 ksi) - **Yield Strength (0.2% Offset):** **≥ 485 MPa** (70 ksi) - **Elongation in 50mm:** **≥ 14%** - **Reduction of Area:** **≥ 40%** - **Machinability:** **Good.** Rating ~65%. The fine, uniform normalized structure allows for stable machining, good surface finish, and predictable tool wear. **C. Enhanced Hardenability (The "B" Advantage):** *The boron addition provides significantly higher hardenability than standard 51xx series steels. For a 13mm round, this guarantees easy and complete through-hardening with a standard oil quench, and provides a substantial safety margin against formation of soft transformation products, ensuring consistent high hardness (e.g., 58-62 HRC as-quenched) throughout the cross-section.* #### **6. Key Characteristics & Value Proposition** - **Cost-Effective Performance:** Delivers hardenability often associated with more expensive alloy steels (e.g., 86xx series) at a lower material cost, offering excellent value for performance. - **Manufacturing Reliability:** The normalized state provides excellent dimensional stability for precision machining, while the boron ensures the heat treatment process is robust and forgiving, reducing scrap rates. - **Consistent Results:** Offers more uniform hardening response across production lots compared to non-boron grades of similar price, leading to more consistent final part performance. - **Weldability (with precautions):** Similar to 5160. Requires preheating (150-260°C / 300-500°F) and proper post-weld heat treatment for critical applications. #### **7. Typical Applications for 13mm Normalized 51B60 Round** This product is specified for high-volume, quality-conscious components requiring reliable hardening: - **Precision Shafts & Pins:** Fuel injection pump shafts, small gearbox shafts, high-strength dowel pins, and actuator rods. - **Automotive Components:** Anti-roll bar links, steering linkage components, valve train parts, and high-strength fasteners (e.g., class 10.9 bolts). - **Hydraulic & Pneumatic Components:** Spool valves, piston rods for compact cylinders, and precision fittings. - **Tooling & Fixtures:** Jig and fixture components, wear pins, and guide rods that require hardening after machining. - **Agricultural & Small Engine Parts:** Crank shafts for small engines, transmission pins, and implement linkages. #### **8. Subsequent Processing Pathway** 1. **Finish Machining:** Perform all final machining operations in this stable, normalized state. 2. **Hardening:** Austenitize at **830-850°C (1525-1560°F)**, then **oil quench**. The boron-enhanced hardenability ensures rapid and complete transformation to martensite in this small diameter. 3. **Tempering:** Temper immediately within **400-540°C (750-1000°F)** to achieve desired final hardness (typically **RC 45-52** for high-strength applications). 4. **Finishing:** Any required grinding, plating, or surface treatment. #### **9. Ordering Information** - **Specify:** AISI 51B60, Normalized, 13 mm (0.5 in.) Round, to ASTM A29. - **Quality Note:** For applications demanding **certified hardenability consistency** (e.g., automotive safety components), specify the **51B60H** grade to **ASTM A304**. - **Certification:** Standard Mill Test Report (MTR) with chemistry is typical. For higher assurance, request mechanical properties from a normalized test coupon. --- **Disclaimer:** The properties listed are for the normalized, pre-hardened condition. **This material must be quenched and tempered for service use.** The boron effect provides enhanced but not guaranteed hardenability; for applications where hardenability must be certified, 51B60H should be specified. Final heat treatment parameters should be validated for specific applications. This material represents an optimal balance of cost and performance for general engineering applications. -:- For detailed product information, please contact sales. -: AISI 51B60 Steel, normalized, 13 mm (0.5 in.) round Specification Dimensions Size： Diameter 20-1000 mm Length <5169 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 51B60 Steel, normalized, 13 mm (0.5 in.) round Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 51B60 Steel, normalized, 13 mm (0.5 in.) round -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 51B60 Steel, normalized, 13 mm (0.5 in.) round -:- For detailed product information, please contact sales. -:

Packing of AISI 51B60 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 1640 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