SUJ 1 High Carbon Bearing Steel Foil/Strip

SUJ 1 High Carbon Bearing Steel Foil (Composition Spec) Product Information -:- For detailed product information, please contact sales. -: SUJ 1 High Carbon Bearing Steel Foil (Composition Spec) Synonyms -:- For detailed product information, please contact sales. -:

SUJ 1 High Carbon Bearing Steel (Composition Spec) Product Information -:- For detailed product information, please contact sales. -: ### **Product Datasheet: SUJ 1 High Carbon Chromium Bearing Steel (JIS G 4805)** --- #### **1. Material Overview** **SUJ 1** is a **high-carbon, chromium alloy steel** defined by the **Japanese Industrial Standard (JIS) G 4805** for high-carbon chromium bearing steels. It is one of three primary grades (SUJ 1, SUJ 2, SUJ 3) in this standard, with SUJ 1 having the **lowest chromium content** of the series. As a through-hardening bearing steel, it is designed to provide a combination of **high hardness, good wear resistance, and moderate fatigue strength** after proper heat treatment. It is suitable for general-purpose bearing applications where the highest level of performance offered by the more alloyed SUJ 2 or SUJ 3 is not required, offering a cost-effective solution for less demanding conditions. #### **2. Key Material Concept: The SUJ Series Chromium Gradient** The SUJ series grades are differentiated primarily by their chromium content, which directly influences hardenability, wear resistance, and cost: - **SUJ 1 (~0.35% Cr):** Provides **basic hardenability and wear resistance**. It is the most economical grade in the series, suitable for smaller sections or applications with moderate loads. - **SUJ 2 (~0.95% Cr):** The **standard and most widely used** bearing steel globally (equivalent to AISI 52100). Offers excellent all-around performance. - **SUJ 3 (~1.45% Cr):** Provides the **deepest hardenability** for large-sized bearings or severe applications. SUJ 1 is selected when the component size and service conditions allow for the use of a lower-hardenability steel, providing a performance-to-cost advantage. #### **3. International Standard & Cross-References** - **Primary Standard:** **JIS G 4805:2019** - High carbon chromium bearing steels. - **ISO Standard:** **ISO 683-17:2014**, Type 2 (Through-hardening bearing steel, low Cr variant). Not a direct one-to-one match. - **ASTM/AISI Equivalent:** There is no direct AISI equivalent with this specific low Cr content. The closest general-purpose high-carbon steel might be **1070** or **1080**, but these lack the specified chromium. - **DIN (German) Equivalent:** No direct equivalent. The closest is **1.3503 (105Cr2)** which has a higher Cr range (0.90-1.20%). - **GB (Chinese) Equivalent:** No direct equivalent in the GCrXX series. - **Common Quality Designation:** Like all SUJ grades, it is typically supplied in **"Bearing Quality"** with controlled inclusion levels. #### **4. Chemical Composition (% by Weight, per JIS G 4805)** | Element | Content Range (%) | Key Role | | :--- | :--- | :--- | | **Carbon (C)** | **0.95 – 1.10** | Primary hardening element; ensures high hardness and forms hard carbides. | | **Silicon (Si)** | **0.15 – 0.35** | Deoxidizer. | | **Manganese (Mn)** | **≤ 0.50** | Enhances hardenability moderately. | | **Phosphorus (P)** | **≤ 0.025** | Impurity; kept very low. | | **Sulfur (S)** | **≤ 0.025** | Impurity; kept very low to improve fatigue life. | | **Chromium (Cr)** | **0.35 – 0.75** | **Defining Characteristic.** Provides basic hardenability, forms some chromium carbides for wear resistance, and improves corrosion resistance slightly. Lower than SUJ2/3. | | **Nickel (Ni)** | **≤ 0.25** | Residual element; controlled. | | **Copper (Cu)** | **≤ 0.25** | Residual element; controlled. | | **Molybdenum (Mo)** | **≤ 0.08** | Residual element; controlled. | #### **5. Typical Physical & Mechanical Properties** **A. Physical Properties:** - **Density:** 7.85 g/cm³ - **Modulus of Elasticity:** ~210 GPa - **Thermal Conductivity:** ~48 W/m·K **B. Mechanical Properties (After Standard Bearing Heat Treatment):** - **Hardness:** **60 – 65 HRC** (after quenching and low-temperature tempering). - **Tensile Strength:** **~2200 MPa** (in the hardened state). - **Core Hardness in Large Sections:** Will be lower than SUJ 2 or SUJ 3 for the same diameter due to lower hardenability. - **Fatigue Strength:** Good, but generally lower than SUJ 2 for equivalent section sizes under high contact stress. **Typical Heat Treatment for Bearings:** 1. **Spheroidize Annealing:** For machinability. 2. **Hardening:** Austenitize at ~800-830°C, **oil quench**. The lower Cr limits the fully hardenable diameter. 3. **Tempering:** 150-200°C to achieve final service hardness while relieving stresses. #### **6. Processing & Fabrication Characteristics** - **Hardenability:** **Moderate.** Suitable for through-hardening of **small to medium sections** (e.g., balls, rollers, and bearing rings of modest cross-section). Larger parts risk a soft pearlitic core. - **Machinability (Annealed):** **Fair.** Similar to other high-carbon steels in the spheroidize annealed condition. - **Grindability:** **Good.** Essential for finishing bearing raceways. - **Weldability:** **Very Poor.** Not recommended for any structural welding. - **Decarburization Sensitivity:** **High.** Requires controlled atmosphere during heat treatment or allowance for stock removal. #### **7. Primary Applications** SUJ 1 is used for general and less severely loaded bearing components: - **Small Bearing Components:** **Balls, rollers, and races for miniature and small-sized ball bearings** (e.g., for electric motors, precision instruments, small appliances). - **General-Purpose Bearings:** Bearings for light-duty machinery, agricultural equipment, and non-critical automotive applications. - **Wear Parts:** **Gauge blocks, straight edges, rollers, and guides** where high hardness is needed but extreme load capacity is not. - **Automotive Components:** Certain **ancillary system bearings** (e.g., idler pulleys, tensioners) where loads are moderate. #### **8. Available Forms & Quality** - **Forms:** Hot-rolled or cold-drawn bars, wire rod (for ball/roller manufacturing), and seamless tubing. - **Quality:** Supplied as **"Bearing Steel"** with controlled non-metallic inclusion content per JIS G 0555 (equivalent to ASTM E45). Standard quality is typical; higher grades (e.g., for improved fatigue life) may be available. #### **9. Comparison within JIS SUJ Series** | Grade | Nominal Cr (%) | Relative Hardenability | Typical Application Size | Relative Cost | | :--- | :--- | :--- | :--- | :--- | | **SUJ 1** | **0.35 – 0.75** | **Lowest** | Small sections, moderate loads | **Most Economical** | | **SUJ 2** | 0.90 – 1.20 | High (Standard) | Most general bearing applications | Standard | | **SUJ 3** | 1.35 – 1.65 | Highest | Large bearings, severe service | Highest | --- **Disclaimer:** SUJ 1 is a specific JIS grade. When specifying, it is crucial to consider the **section size and required core hardness** to ensure adequate hardenability. For applications where full through-hardening is critical, **SUJ 2 should be the default choice.** The properties listed are typical; actual performance depends on heat treatment, section size, and steel cleanliness. For international projects, specifying the more common SUJ 2 or its ASTM/ISO equivalents (52100/100Cr6) is often preferred for supply chain simplicity unless a specific cost/performance benefit for SUJ 1 is identified. -:- For detailed product information, please contact sales. -: SUJ 1 High Carbon Bearing Steel (Composition Spec) Specification Dimensions Size： Diameter 20-1000 mm Length <5197 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. -: SUJ 1 High Carbon Bearing Steel (Composition Spec) Properties -:- For detailed product information, please contact sales. -:

Applications of SUJ 1 High Carbon Bearing Steel Foil (Composition Spec) -:- For detailed product information, please contact sales. -: Chemical Identifiers SUJ 1 High Carbon Bearing Steel Foil (Composition Spec) -:- For detailed product information, please contact sales. -:

Packing of SUJ 1 High Carbon Bearing Steel Foil/Strip (Composition Spec) -:- 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 Foil/Strip 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 1668 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