1,We Manufacturing processes are primarily classified into four types:
1:Forging,
2:Casting,
3:Cutting,
4:Rolling.
2,We can manufacture in accordance with these standards.
Standards:
GB Series (Chinese Standards), JB Series (Machinery Standards), HG Series (Chemical Industry Standards), ASME B16.5 (American Standards), BS4504 (British Standards), DIN (German Standards), and JIS (Japanese Standards).
Internationally, there are two primary systems of pipe flange standards: the European system, represented by the German DIN standards (including those of the former Soviet Union), and the American system, represented by the US ANSI pipe flange standards. Other common standards include: the Chinese Ministry of Machinery Industry standards (JB series), the Ministry of Chemical Industry standards (HG series), the Chinese National Standard *GB/T 9112–9124-2010 Steel Pipe Flanges*, as well as US standards (ASME B16.5), British standards (BS4504), German standards (DIN), Japanese standards (JIS), and marine standards (CBM), among others.
The nominal pressure ratings for the PN series are designated by "PN" and comprise the following nine levels: PN2.5, PN6, PN10, PN16, PN25, PN40, PN63, PN100, and PN160.
The nominal pressure ratings for the Class series are designated by "Class" and comprise the following six levels: Class150, Class300, Class600, Class900, Class1500, and Class2500.
Flange Classification
1. **According to Chemical Industry Standards:** Flanges are classified as follows:
Plate Flat Welding Flange (PL), Necked Flat Welding Flange (SO), Necked Butt Welding Flange (WN), Integral Flange (IF), Socket Welding Flange (SW), Threaded Flange (Th), Butt Welding Ring Loose Flange (PJ/SE), Blind Flange (BL), Flat Welding Ring Loose Flange (PJ/PJ), and Lined Blind Flange (BL(s)).
2. **According to Petrochemical (SH) Industry Standards:** Flanges are classified as follows:
Threaded Flange (PL), Butt Welding Flange (WN), Flat Welding Flange (SO), Socket Welding Flange (SW), Loose Flange (LJ), and Blind Flange (no specific designation).
3. **According to Machinery (JB) Industry Standards:** Flanges are classified as follows:
Integral Flange, Butt Welding Flange, Plate Flat Welding Flange, Butt Welding Ring Plate Loose Flange, Flat Welding Ring Plate Loose Flange, Lap Joint Ring Plate Loose Flange, and Blind Flange.
4. **According to Connection Method/Type:** Flanges are classified as follows:
Plate Flat Welding Flange, Necked Flat Welding Flange, Necked Butt Welding Flange, Socket Welding Flange, Threaded Flange, Blind Flange, Necked Butt Welding Ring Loose Flange, Flat Welding Ring Loose Flange, Ring-Type Joint (RTJ) Flange and Blind Flange, Large-Diameter Plate Flange, Large-Diameter High-Neck Flange, Figure-8 Blind Plate, Butt Welding Ring Loose Flange, etc.
5. **According to the Component Being Connected:** Flanges can be classified into Vessel Flanges and Pipe Flanges.
6. **According to Structural Type:** Flanges include Integral Flanges, Threaded Flanges, Flat Welding Flanges, Butt Welding Flanges, Lap Joint (Loose/Swivel) Flanges, and Blind Flanges.
A flange—also referred to as a flange plate or rim—is a component used to connect shafts to one another, or, more commonly, to join the ends of pipes. Flanges are also utilized at the inlet and outlet ports of equipment to facilitate connections between two devices—for instance, the flange on a speed reducer. A "flange connection" or "flanged joint" refers to a detachable joint assembly comprising three interconnected elements—a flange, a gasket, and bolts—that together form a sealed structural unit. In the context of piping systems, a "pipe flange" specifically denotes a flange used for plumbing within the installation; when applied to equipment, it refers to the inlet or outlet flange of that specific device. Flanges feature a series of holes through which bolts are inserted to securely fasten the two flanges together, while a gasket placed between the flanges ensures a leak-proof seal. Flanges are broadly categorized into three types: threaded (screw-in) flanges, welded flanges, and clamp-type flanges. Flanges are invariably used in pairs; threaded flanges are suitable for low-pressure piping applications, whereas welded flanges are required for systems operating at pressures exceeding 4 kilograms per square centimeter. A sealing gasket is inserted between the two flange plates, which are then firmly secured using bolts. The thickness of a flange—as well as the specifications of the bolts used to fasten it—vary depending on the specific pressure rating required for the application. When connecting equipment such as water pumps or valves to piping systems, the corresponding connection points on these devices are often manufactured in the shape of a matching flange; this method of attachment is also referred to as a "flange connection." Generally, any connecting component that utilizes bolts to join and seal the perimeters of two flat surfaces—such as the joints in ventilation ducts—is termed a "flange"; such components may collectively be classified as "flange-type parts." However, since such a connection often constitutes merely a *portion* of a larger device—for instance, the interface between a flange and a water pump—it would be inappropriate to classify the entire water pump itself as a "flange-type part." Conversely, smaller components—such as valves—that feature such flanged interfaces may indeed be appropriately categorized as "flange-type parts."
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JIS SKS2 Oil-Hardening Cold Work Tool Steel Flange Product Information
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JIS SKS2 Oil-Hardening Cold Work Tool Steel Flange Synonyms
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JIS SKS2 Oil-Hardening Cold Work Tool Steel Product Information
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# **JIS SKS2 Oil-Hardening Cold Work Tool Steel**
**International Standard:** JIS G4404 (Japan Industrial Standard) - Tool Steels
---
## **1. Overview**
JIS SKS2 is a **medium-carbon, low-alloy oil-hardening cold work tool steel** belonging to the SKS (Silicon-Chromium) series. Characterized by its **good machinability, minimal distortion during heat treatment, and excellent wear resistance after hardening**, SKS2 is a versatile and economical choice for a wide range of cold work tooling applications. It offers a balanced combination of hardness, toughness, and dimensional stability, making it particularly suitable for intricate tools and parts requiring precise heat treatment with minimal size change.
---
## **2. Chemical Composition (Typical Weight %)**
| Element | Content (%) |
| :------ | :---------- |
| C | 0.95–1.10 |
| Si | 0.15–0.35 |
| Mn | 0.90–1.20 |
| Cr | 0.50–1.00 |
| W | 0.50–1.00 |
| V | 0.10–0.25 |
| P (max) | 0.030 |
| S (max) | 0.030 |
**Balance:** Iron (Fe).
**Key Characteristics:** SKS2 features a **moderate alloy content with tungsten and chromium** for hardenability and wear resistance, while maintaining a composition that ensures good machinability in the annealed state and relatively low distortion during oil quenching. The combination of around 1% carbon with these alloying elements allows it to achieve good hardness while retaining reasonable toughness.
---
## **3. Physical & Mechanical Properties**
### **Physical Properties**
- **Density:** ~7.83 g/cm³
- **Thermal Conductivity:** ~45 W/m·K (at 20°C) – Relatively good for a tool steel
- **Coefficient of Thermal Expansion:** ~12.5 ×10⁻⁶ /K (20–200°C)
- **Specific Heat Capacity:** ~0.46 kJ/kg·K
- **Modulus of Elasticity:** ~210 GPa
### **Mechanical Properties (Heat-Treated)**
- **Annealed Hardness:** 187–229 HB
- **Hardened & Tempered Hardness:** **57–62 HRC** (typical working range)
- **Tensile Strength:** ~2000–2200 MPa (at 60 HRC)
- **Yield Strength:** ~1800–2000 MPa
- **Elongation:** ~5–10% (depending on hardness)
- **Impact Toughness:** **Good** – Better than many high-alloy cold work steels at similar hardness
- **Wear Resistance:** **Good** – Suitable for many cold work applications
- **Compressive Strength:** ~2500–2800 MPa
---
## **4. Heat Treatment Specifications**
### **1. Annealing**
- **Temperature:** 750–800°C
- **Process:** Heat uniformly, hold for 2–4 hours, furnace cool slowly (≤ 20°C/h) to 550°C, then air cool
- **Resulting Hardness:** 187–229 HB (optimal for machining)
- **Spheroidize Annealing:** Recommended for best machinability: 760–780°C, hold 4–6 hours, cool slowly (10°C/h) to 600°C
### **2. Stress Relieving**
- **Temperature:** 600–650°C
- **Hold Time:** 1–2 hours per 25mm thickness
- **Cooling:** Air cool
- **Purpose:** Reduce machining stresses, minimize distortion during final hardening
### **3. Hardening (Quenching)**
- **Preheating:** Recommended for complex parts
- **First Preheat:** 400–500°C (optional but beneficial)
- **Second Preheat:** 700–750°C (recommended for uniform heating)
- **Austenitizing Temperature:** **780–850°C** (typically 800–830°C)
- **Soaking Time:** 20–30 minutes per 25mm at temperature
- **Quenching Medium:** **Oil** (warm oil at 40–80°C recommended for minimal distortion)
- **Quenching Temperature:** Quench from austenitizing temperature to 50–70°C
### **4. Tempering**
- **Immediate Tempering Required:** Begin when tool reaches 50–80°C
- **Temperature Range:** **150–250°C** for maximum hardness (58–62 HRC)
- Can be tempered at higher temperatures (up to 500°C) for increased toughness with reduced hardness
- **Hold Time:** 1–2 hours per 25mm thickness, minimum 1 hour
- **Cycles:** Single temper usually sufficient; double tempering improves dimensional stability for precision tools
### **5. Sub-Zero Treatment**
- **Generally Not Required:** Due to low retained austenite content
- **Optional:** For maximum dimensional stability in precision tools, treat at -70 to -100°C before tempering
---
## **5. Key Features & Advantages**
1. **Minimal Distortion:** Oil quenching results in less distortion and size change compared to water-hardening steels, ideal for intricate tools
2. **Good Machinability:** In annealed condition, offers excellent machinability compared to higher-alloy tool steels
3. **Economical:** Lower alloy content makes it more cost-effective than many other tool steels
4. **Good Toughness-Hardness Balance:** Achieves good hardness while maintaining reasonable impact resistance
5. **Versatile Heat Treatment:** Can be heat treated with relatively simple equipment
6. **Good Wear Resistance:** Adequate for many cold work applications
7. **Relatively Deep Hardening:** Sufficient hardenability for medium-sized sections
**Limitations:**
- **Limited Hot Hardness:** Not suitable for applications involving significant heat generation
- **Moderate Wear Resistance:** Less wear resistant than higher-alloy steels like D2 or high-speed steels
- **Section Size Limitations:** Hardenability limited compared to air-hardening grades
---
## **6. Typical Applications**
SKS2 is widely used for various **cold work tooling applications** where good wear resistance, reasonable toughness, and economical cost are important.
### **Cutting & Shearing Tools:**
- **Hand Tools:** Chisels, punches, screwdrivers, cold chisels
- **Cutting Blades:** Leather cutting knives, paper cutting blades, fabric cutters
- **Shear Blades:** For cutting soft metals, plastics, and other materials
- **Woodworking Tools:** Planer blades, carving tools
### **Forming Tools:**
- **Punches and Dies:** For blanking, piercing, and forming of mild steel, brass, aluminum
- **Bending Tools:** Press brake dies and punches
- **Drawing Dies:** For shallow drawing operations
- **Thread Rolling Dies:** For softer materials
- **Knurling Tools:** For producing patterns on cylindrical surfaces
### **Measuring & Precision Tools:**
- **Gauges:** Plug gauges, ring gauges, thread gauges
- **Template:** For inspection and layout
- **Machine Parts:** Bushings, wear plates, guide pins
### **Miscellaneous Tooling:**
- **Lathe Centers:** For supporting workpieces
- **Marking Tools:** Scribers, center punches
- **Slitting Saws:** For cutting non-ferrous metals and plastics
- **Embossing Dies:** For decorative work
---
## **7. International Standard Equivalents**
| Standard | Grade Designation | Notes |
| :--------------- | :------------------ | :----------------------------------------- |
| **JIS** | SKS2 | Original specification (JIS G4404) |
| **AISI/SAE (USA)**| O1 | **Direct Equivalent** (Oil-hardening 1) |
| **DIN (Germany)** | 1.2510 | Close equivalent |
| **ISO** | 95MnWCr1 | International designation |
| **BS (UK)** | BO1 | British standard |
| **GB (China)** | 9CrWMn | Similar composition |
| **UNS** | T31501 | Unified Numbering System |
---
## **8. Machining & Fabrication Guidelines**
### **Machining (In Annealed State):**
- **Excellent Machinability:** One of the most machinable tool steels
- **Tooling:** High-speed steel tools work well; carbide for production
- **Cutting Speeds:** Can use higher speeds than most tool steels
- **Feeds:** Moderate to heavy feeds possible
- **Chip Control:** Produces discontinuous chips; use chipbreakers
### **Grinding:**
- **Good Grindability:** Responds well to grinding operations
- **Wheel Selection:** Aluminum oxide wheels (A46-JV or similar)
- **Coolant:** Use coolant to prevent overheating and maintain hardness
- **Parameters:** Standard grinding parameters suitable
### **Electrical Discharge Machining (EDM):**
- **Suitable:** Can be EDMed in hardened or annealed state
- **Post-EDM:** Temper at 150–180°C to relieve stresses from white layer
### **Welding:**
- **Possible with Care:** Can be welded using appropriate techniques
- **Preheat:** 200–300°C recommended
- **Filler Material:** Use matching or slightly lower carbon filler
- **Post-Weld:** Anneal or re-harden entire tool for best results
---
## **9. Surface Treatment**
### **1. Nitriding:**
- **Effective Treatment:** Improves surface hardness and wear resistance
- **Process:** Gas or liquid nitriding at 500–550°C
- **Case Depth:** 0.1–0.3 mm typical
- **Surface Hardness:** 700–900 HV
- **Caution:** May reduce core hardness if temperature exceeds tempering temperature
### **2. Carburizing:**
- **Occasionally Used:** For special applications requiring very high surface carbon
- **Process:** Pack or gas carburizing
- **Result:** Creates high-carbon case on medium-carbon core
### **3. Phosphate Coating:**
- **Common for Some Tools:** Improves corrosion resistance and lubricity
- **Application:** Often used on punches and dies
### **4. Chrome Plating:**
- **For Corrosion Resistance:** Thin decorative or hard chrome
- **For Wear Resistance:** Hard chrome plating (0.01–0.05 mm)
---
## **10. Performance Comparison**
### **Within Oil-Hardening Tool Steel Family:**
| Property | SKS2 (O1) | SKS3 (O2) | SKS21 (L6) | SKS4 (W1) |
|-----------------------|--------------|--------------|--------------|--------------|
| **Carbon Content** | 0.95–1.10% | 0.85–0.95% | 0.70–0.80% | 1.00–1.10% |
| **Alloy Content** | Medium | Low | Medium | Very Low |
| **Distortion** | Low | Very Low | Low | High |
| **Machinability** | Excellent | Excellent | Good | Excellent |
| **Hardenability** | Good | Fair | Good | Poor |
| **Wear Resistance** | Good | Fair | Good | Fair |
| **Toughness** | Good | Very Good | Excellent | Fair |
### **Compared to Other Cold Work Steels:**
| Property | SKS2 (O1) | SKD11 (D2) | SKD1 (A2) | SKS8 (A6) |
|-----------------------|--------------|--------------|--------------|--------------|
| **Hardening Method** | Oil | Air | Air | Air |
| **Max Hardness** | 62 HRC | 62 HRC | 62 HRC | 62 HRC |
| **Distortion** | Low | Very Low | Very Low | Very Low |
| **Wear Resistance** | Good | Excellent | Very Good | Good |
| **Toughness** | Good | Fair | Very Good | Excellent |
| **Machinability** | Excellent | Fair | Good | Good |
| **Cost** | Low | High | Medium | Medium |
---
## **11. Design & Manufacturing Considerations**
### **Section Size Limitations:**
- **Fully Hardenable:** Up to approximately 25 mm diameter/ thickness
- **Surface Hardening Only:** Up to 75 mm (with reduced core hardness)
- **Large Sections:** Consider air-hardening grades for sections > 75 mm
### **Stress Relief:**
- **Essential After Rough Machining:** Minimizes distortion during final hardening
- **Temperature:** 600–650°C
- **Before Hardening:** Always stress relieve complex or heavily machined tools
### **Dimensional Changes:**
- **During Heat Treatment:** Typically 0.05–0.15% growth
- **During Tempering:** Minimal change
- **Design Allowance:** Include appropriate machining allowance for finishing after hardening
### **Tool Geometry:**
- **Avoid Sharp Corners:** Radius all corners (minimum 0.5 mm) to prevent cracking
- **Uniform Sections:** Design for uniform wall thickness where possible
- **Gradual Transitions:** Use generous fillets and tapers
---
## **12. Quality Control**
### **Hardness Testing:**
- **Rockwell C Scale:** For hardened material
- **Brinell or Rockwell B:** For annealed material
- **Multiple Readings:** Take at various locations for uniformity
### **Microstructure Examination:**
- **Annealed Condition:** Spheroidized carbides in ferritic matrix
- **Hardened Condition:** Fine tempered martensite with dispersed carbides
- **Grain Size:** ASTM 8 or finer desired
### **Non-Destructive Testing:**
- **Magnetic Particle:** For surface cracks after heat treatment
- **Dye Penetrant:** Alternative for non-magnetic applications
- **Dimensional Verification:** Critical for precision tools
---
## **13. Summary & Selection Guidelines**
JIS SKS2 (AISI O1) is a **versatile, economical oil-hardening cold work tool steel** that offers an excellent balance of properties for a wide range of tooling applications.
### **Select SKS2 When:**
1. **Good machinability** is important for tool manufacturing
2. **Minimal distortion** during heat treatment is required
3. **Tool complexity** necessitates oil quenching for dimensional control
4. **Cost-effectiveness** is a significant consideration
5. **Wear resistance requirements** are moderate
6. **Tool size** is within its hardenability limits
7. **Toughness** needs to be balanced with hardness
### **Optimal Application Examples:**
- **Intricate punches and dies** requiring precise dimensions
- **Hand tools** needing good edge retention
- **Prototype tooling** where machinability speeds development
- **Low-to-medium production** tooling
- **Tools subject to moderate impact** as well as wear
### **Consider Alternatives When:**
- **Extreme wear resistance** is needed (consider D2 or high-speed steels)
- **Very high toughness** is primary requirement (consider SKS21/L6)
- **Large section sizes** exceed hardenability limits (consider air-hardening grades)
- **High temperature** operation is involved (consider hot work steels)
- **Maximum dimensional stability** is critical (consider air-hardening grades)
### **Economic Advantages:**
- **Lower material cost** than most alloy tool steels
- **Reduced machining costs** due to excellent machinability
- **Lower heat treatment costs** compared to some air-hardening grades
- **Good tool life** for many applications
### **Heat Treatment Simplicity:**
SKS2's oil-hardening characteristics make it suitable for shops with basic heat treatment facilities. The relatively low hardening temperature (780–850°C) and oil quenching requirement make it accessible for many toolrooms.
### **Versatility:**
From simple hand tools to complex dies, SKS2 serves well across a broad spectrum of cold work applications. Its balanced properties make it a "go-to" steel for many general-purpose tooling needs.
### **Final Recommendation:**
JIS SKS2 remains a **highly relevant and widely used tool steel** for applications where its combination of machinability, dimensional stability during heat treatment, and good wear resistance at reasonable cost provides optimal value. For many cold work tooling applications, especially those involving complex geometries or where tool manufacturing efficiency is important, SKS2 continues to be an excellent choice that has stood the test of time in toolrooms worldwide.
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JIS SKS2 Oil-Hardening Cold Work Tool Steel Specification
Dimensions
Size:
Diameter 20-1000 mm Length <6819 mm
Size:We can customized as required
Standard:
Per your request or drawing
We can customized as required
Properties(Theoretical)
Chemical Composition
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JIS SKS2 Oil-Hardening Cold Work Tool Steel Properties
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Applications of JIS SKS2 Oil-Hardening Cold Work Tool Steel Flange
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Chemical Identifiers JIS SKS2 Oil-Hardening Cold Work Tool Steel Flange
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Packing of JIS SKS2 Oil-Hardening Cold Work Tool Steel Flange
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Standard Packing:
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Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Flange 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 3290 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