Carpenter,S7 Alloy Tool Steel Tube,Pipe (AISI S7)

Carpenter S7 Alloy Tool Steel Tube (AISI S7) Product Information -:- For detailed product information, please contact sales. -: Carpenter S7 Alloy Tool Steel Tube (AISI S7) Synonyms -:- For detailed product information, please contact sales. -:

Carpenter S7 Alloy Tool Steel (AISI S7) Product Information -:- For detailed product information, please contact sales. -: # **Carpenter S7 Alloy Tool Steel (AISI S7)** ## **Premium Shock-Resisting Air-Hardening Tool Steel for Extreme Impact Applications** --- ### **Product Overview** Carpenter S7 Alloy is a premium shock-resisting, air-hardening tool steel corresponding to the AISI S7 classification, renowned for its **exceptional impact toughness, high fatigue strength, and good resistance to deformation under shock loading**. As one of the toughest tool steels commercially available, S7 provides outstanding performance in applications subjected to severe impact, repeated shock loading, and high stress concentrations. Characterized by its medium carbon content and balanced chromium-molybdenum-silicon alloy system, this material maintains high hardness (up to 58 HRC) while offering fracture toughness superior to most other tool steels, making it ideal for demanding applications where resistance to chipping, cracking, and catastrophic failure is paramount. --- ### **Key Advantages** - **Exceptional Impact Toughness**: Superior resistance to fracture under shock loading conditions - **High Fatigue Strength**: Excellent performance under cyclic loading and repeated impacts - **Good Wear Resistance**: Maintains adequate abrasion resistance despite high toughness - **Air-Hardening Characteristics**: Minimal distortion during heat treatment - **Deep Hardening Capability**: Through-hardens in air up to 150mm (6 inches) sections - **Good Machinability**: Better than many high-alloy tool steels in annealed condition - **Versatile Heat Treatment**: Can be hardened to various hardness levels for specific applications - **Reliable Performance**: Consistent, predictable behavior in demanding service conditions --- ### **Chemical Composition (%)** | Element | Carbon (C) | Chromium (Cr) | Molybdenum (Mo) | Silicon (Si) | Manganese (Mn) | |---------|------------|---------------|-----------------|--------------|----------------| | **Content** | 0.45-0.55 | 3.00-3.50 | 1.30-1.80 | 0.20-0.90 | 0.20-0.80 | *Additional Elements:* - Vanadium (V): ≤0.35% - Nickel (Ni): ≤0.25% - Copper (Cu): ≤0.25% - Phosphorus (P): ≤0.030% - Sulfur (S): ≤0.030% *Special Characteristics:* - **Medium Carbon Content**: Optimized for toughness while maintaining hardenability - **Balanced Chromium-Molybdenum**: Provides deep hardening and temper resistance - **Silicon Enhancement**: Contributes to strength and tempering resistance - **Low Impurity Levels**: Minimized to maximize toughness and fatigue resistance --- ### **Physical & Mechanical Properties** #### **Physical Properties** - **Density**: 7.80 g/cm³ (0.282 lb/in³) - **Melting Point**: 1420-1460°C (2590-2660°F) - **Thermal Conductivity**: 32.5 W/m·K at 20°C - **Coefficient of Thermal Expansion**: 11.5 × 10⁻⁶/°C (20-100°C) - **Modulus of Elasticity**: 205 GPa (29.7 × 10⁶ psi) - **Specific Heat**: 460 J/kg·K at 20°C - **Electrical Resistivity**: 0.28 μΩ·m at 20°C #### **Mechanical Properties** **Annealed Condition (typical):** - Hardness: 190-220 HB - Ultimate Tensile Strength: 650-750 MPa (94-109 ksi) - Yield Strength: 380-480 MPa (55-70 ksi) - Elongation: 20-25% - Reduction of Area: 40-50% - Machinability Rating: 70% (relative to 1% carbon steel, 100%) **Hardened and Tempered Condition:** - **Typical Hardness Range**: **54-58 HRC** (optimal 56-57 HRC for maximum toughness) - Ultimate Tensile Strength: 1800-2000 MPa (261-290 ksi) - Yield Strength: 1500-1700 MPa (218-247 ksi) - Elongation: 10-15% - Reduction of Area: 25-35% - **Impact Toughness (Charpy V-notch)**: **40-60 J (30-44 ft-lb)** at 56 HRC (exceptional) - Compressive Strength: 2000-2300 MPa (290-334 ksi) - Transverse Rupture Strength: 3000-3500 MPa (435-508 ksi) - **Fatigue Strength** (10⁷ cycles): 700-800 MPa (102-116 ksi) - **Abrasion Resistance**: Comparable to A2 at equivalent hardness levels **Hardenability Characteristics:** - Fully hardenable in air up to 150mm (6 inches) diameter - Surface hardness of 58-60 HRC achievable on hardening - Through-hardness typically 1-3 HRC points lower than surface - Dimensional change: typically +0.03% to +0.07% on hardening - Excellent resistance to quenching cracking due to air-hardening nature #### **Heat Treatment Parameters** 1. **Annealing:** - Temperature: 790-815°C (1450-1500°F) - Cooling: Slow furnace cool to 540°C (1000°F) at 15°C (25°F)/hour, then air cool - Resulting hardness: 190-220 HB - *For spheroidized structure: Hold at 760-790°C (1400-1450°F) for extended time* 2. **Stress Relieving (after rough machining):** - Temperature: 650-675°C (1200-1250°F) for 1-2 hours - Air cool 3. **Preheating:** - Temperature: 650-700°C (1200-1290°F) - Soak time: 30-60 minutes per inch of thickness 4. **Austenitizing:** - Temperature: **925-955°C (1700-1750°F)** - Soak time: 30-60 minutes per inch of thickness - *Critical: Lower temperatures (925-940°C) for maximum toughness* 5. **Quenching:** - Medium: Still air or forced air (air hardening) - Cooling rate: Approximately 15-25°C (27-45°F) per minute - *For maximum toughness: Use interrupted cooling at 200-250°C (390-480°F)* - Cool to below 50°C (120°F) before tempering 6. **Tempering:** - **Tempering within 4 hours of quenching recommended** - Temperature range: **175-650°C (350-1200°F)** - Double tempering recommended for maximum toughness and stability - Typical tempering response: - 175°C (350°F): 57-59 HRC - 205°C (400°F): 56-58 HRC - 260°C (500°F): 55-57 HRC - 315°C (600°F): 53-55 HRC - 425°C (800°F): 50-52 HRC - 540°C (1000°F): 45-47 HRC - 650°C (1200°F): 38-40 HRC - Duration: 1-2 hours per inch of thickness, minimum 2 hours - Between tempers: Cool to room temperature - *Note: Tempering above 315°C (600°F) significantly enhances toughness* --- ### **International Standards & Cross-References** | Standard System | Designation | Notes | |----------------|-------------|-------| | **Carpenter** | S7 Alloy | Proprietary name for premium S7 steel | | **AISI** | S7 | Standard shock-resisting tool steel | | **UNS** | T41907 | Unified Numbering System | | **ISO** | - | No direct ISO equivalent | | **European (EN)** | - | Not standardized in EN system | | **German (DIN)** | 1.2542 | Similar shock-resisting steel | | **British (BS)** | - | Not standardized in BS system | | **Japanese (JIS)** | - | No direct equivalent | | **Common Equivalents** | AISI Type S7, Shock Steel Grade S7 | Commercial equivalents | --- ### **Typical Applications** #### **1. Shock and Impact Tools** - **Chisels and Punches**: For demolition, construction, and heavy fabrication - **Pneumatic Tool Components**: Jackhammer bits, rock drill parts, impact hammers - **Blacksmith Tools**: Hammers, sledges, anvil tools - **Mining and Quarrying Tools**: Pick points, crusher parts, drilling equipment - **Cold Chisels and Wedges**: For splitting and breaking operations #### **2. Shear and Cutting Tools for Tough Materials** - **Shear Blades**: For cutting high-strength alloys, thick plates, and tough materials - **Slitter Knives**: For difficult-to-cut metals and alloys - **Scrap Chopper Blades**: For recycling and scrap processing - **Wood Chipper Knives**: For heavy-duty wood processing - **Bolt Cutters and Heavy Snips**: For cutting hardened fasteners and materials #### **3. Forming and Stamping Tools** - **Cold Forging Dies**: For high-impact forming operations - **Punching and Blanking Dies**: For thick materials and high-impact applications - **Thread Rolling Dies**: For tough or hard materials - **Heavy Forming Dies**: For automotive and heavy equipment components - **Coining Dies**: Where impact resistance is critical #### **4. Plastic and Rubber Processing** - **Heavy-Duty Injection Molds**: For thick-section parts and abrasive materials - **Compression Molds**: For rubber and thermoset plastics - **Extrusion Dies**: For abrasive plastic compounds - **Mold Components**: Subject to high clamping forces and impact #### **5. Specialized Industrial Components** - **Gears and Shafts**: For heavy machinery subject to shock loads - **Wear Plates and Liners**: In high-impact, abrasive environments - **Bushings and Bearings**: For high-load, low-speed applications - **Machine Tool Components**: Subject to vibration and impact - **Safety Critical Components**: Where failure would be catastrophic --- ### **Machining & Fabrication Guidelines** #### **In Annealed Condition (190-220 HB)** - **Machinability**: Good (70% of 1% carbon steel) - **Recommended Cutting Tools**: High-speed steel or carbide - **Turning Speeds**: 60-80 SFM with HSS, 180-250 SFM with carbide - **Milling Speeds**: 50-70 SFM with HSS, 150-220 SFM with carbide - **Drilling Speeds**: 35-50 SFM with HSS drills - **Coolant**: Recommended for best results and tool life - **Chip Characteristics**: Produces manageable chips with proper tool geometry #### **Grinding and Finishing** - **Hardened State Grinding**: Good grindability despite hardness - **Wheel Selection**: Use aluminum oxide (46-60 grit, H-I hardness) or CBN wheels - **Grinding Parameters**: Medium passes with adequate coolant - **Surface Finish**: Capable of achieving 0.4-0.8 μm (16-32 μin) Ra with proper technique - **Electrical Discharge Machining (EDM)**: Excellent results; stress relieve after #### **Welding and Joining** - **Weldability**: Good with proper procedures - **Recommended Methods**: TIG or MIG with preheating (200-300°C / 400-570°F) - **Filler Material**: Matching composition or high-nickel alloys - **Post-Weld Heat Treatment**: Stress relieve at 550-600°C (1020-1110°F) - **Hardening After Welding**: Possible with full re-austenitizing and air cooling --- ### **Surface Treatment Compatibility** #### **Recommended Treatments** - **Nitriding**: Gas or plasma nitriding for increased surface hardness (65-68 HRC) - **Hard Chrome Plating**: For improved wear and corrosion resistance - **Phosphate Coating**: For improved lubrication in forming applications - **Black Oxide**: For corrosion resistance and appearance - **Titanium Nitride (TiN) Coating**: PVD coating for specific applications #### **Benefits of Surface Treatments** - **Extended Tool Life**: 50-200% improvement with appropriate treatments - **Enhanced Wear Resistance**: Surface hardness up to 68 HRC with nitriding - **Corrosion Protection**: Improved resistance to rust and chemical attack - **Reduced Friction**: Better material flow in forming applications - **Improved Fatigue Strength**: Surface compressive stresses from nitriding --- ### **Comparison with Similar Tool Steels** | Property | S7 | A2 | D2 | H13 | L6 | |----------|----|----|----|-----|----| | **Impact Toughness** | **Excellent** | Good | Fair | Very Good | Very Good | | **Wear Resistance** | Good | Very Good | Excellent | Good | Good | | **Maximum Hardness (HRC)** | 58-60 | 62-64 | 62-64 | 48-52 | 62-64 | | **Fatigue Strength** | **Excellent** | Good | Fair | Very Good | Good | | **Machinability** | Good | Good | Fair | Good | Good | | **Heat Treatment** | Air-hardening | Air-hardening | Air-hardening | Air-hardening | Oil-hardening | | **Primary Application** | Shock tools | General tooling | High-wear tools | Hot work tools | Tough tooling | | **Cost Factor** | Medium-High | Medium | Medium | Medium | Medium | --- ### **Design and Manufacturing Considerations** #### **Optimal Design Practices** - **Generous Radii**: Minimum 3mm (0.125") on internal corners in high-stress areas - **Gradual Section Transitions**: Avoid abrupt changes in cross-section - **Balanced Designs**: To distribute impact loads evenly - **Adequate Section Size**: Minimum 10mm (0.4") for through-hardening in critical applications - **Stress Relief Features**: Proper fillets and chamfers at stress concentrations #### **Heat Treatment Best Practices** 1. **Thorough Preheating**: Essential for complex shapes and thick sections 2. **Controlled Austenitizing**: Lower temperatures for maximum toughness 3. **Uniform Heating**: Ensure even temperature throughout the part 4. **Controlled Cooling**: Still air for simple shapes, forced air for uniformity 5. **Proper Tempering**: Multiple tempers for maximum toughness development 6. **Temperature Uniformity**: Critical during all heat treatment stages #### **Common Pitfalls to Avoid** - Over-austenitizing (reduces toughness through grain growth) - Insufficient preheating for complex shapes - Inadequate tempering (insufficient toughness development) - Using contaminated atmosphere during heating - Grinding burns (can create surface cracks in hardened state) --- ### **Economic Justification** #### **Cost-Benefit Analysis** - **Reduced Tool Failure**: Exceptional toughness minimizes catastrophic failures - **Extended Service Life**: Good wear resistance combined with superior impact resistance - **Lower Maintenance Costs**: Fewer repairs and less downtime - **Improved Safety**: Reduced risk of tool fragmentation in high-impact applications - **Versatile Application**: One material for multiple demanding applications **Typical ROI**: 3-12 months in heavy industrial and tooling applications #### **Total Cost Factors** 1. **Material Cost**: Higher than general-purpose tool steels 2. **Manufacturing Cost**: Moderate due to good machinability 3. **Heat Treatment Cost**: Simple air hardening (low energy costs) 4. **Tool Performance**: Exceptional for impact and shock applications 5. **Maintenance**: Easy to repair and rework compared to oil-hardening grades --- ### **Industry-Specific Applications** #### **Construction and Mining** - **Demolition Tools**: Jackhammer bits, concrete breakers, paving breakers - **Excavation Equipment**: Tooth points, cutting edges, ripper tips - **Drilling Tools**: Rock drill bits, down-the-hole hammers - **Quarrying Equipment**: Crusher parts, screening equipment components #### **Heavy Manufacturing** - **Forging and Stamping**: Die components for automotive and heavy equipment - **Metal Processing**: Shear blades for plate and structural steel - **Heavy Machinery**: Gears, shafts, and impact-resistant components #### **Aerospace and Defense** - **Landing Gear Components**: High-stress pins, bushings, and linkages - **Weapon Systems**: Firearm components subject to high impact - **Tooling for Composites**: Cutting and trimming tools for CFRP - **Ground Support Equipment**: Heavy-duty tools and fixtures #### **Oil and Gas Industry** - **Downhole Tools**: Impact components for drilling and completion - **Valve Components**: For high-pressure, high-shock applications - **Pipeline Tools**: Cutting and beveling equipment for heavy-wall pipe --- ### **Technical Specifications & Quality Assurance** #### **Quality Standards** - **Micro-Cleanliness**: Meets or exceeds ASTM E45 requirements - **Grain Size**: ASTM 6-8 (fine to medium) - **Decarburization**: Controlled to ≤0.30mm (0.012") per side - **Hardness Uniformity**: Consistent through specified sections - **Ultrasonic Testing**: Available for critical applications #### **Available Forms** - **Round Bars**: 10mm to 400mm diameter - **Flat Bars and Plates**: Various thicknesses up to 300mm - **Forgings**: Custom shapes and sizes - **Blocks**: Up to 500mm thickness - **Pre-finished Blanks**: Ground, stress-relieved, or rough machined - **Special Sections**: Squares, hexagons, and custom profiles #### **Certification** - Mill test certificates with full chemical analysis - Hardness and mechanical test reports - Impact test data (Charpy V-notch available upon request) - Microstructure and grain size reports - Full traceability to heat and melt numbers --- ### **Safety and Environmental Considerations** #### **Material Safety** - Standard steel handling precautions apply - Grinding dust requires proper ventilation and collection - Material safety data sheets available - No special handling requirements beyond normal steel precautions #### **Regulatory Compliance** - ROHS compliant - REACH registered - Conforms to international environmental standards - Suitable for food contact applications with proper surface treatment --- ### **Conclusion** Carpenter S7 Alloy (AISI S7) represents the pinnacle of shock-resistant tool steel technology, offering unparalleled impact toughness and fatigue resistance for the most demanding industrial applications. Its unique combination of properties makes it the material of choice where resistance to catastrophic failure under impact loading is more critical than maximum wear resistance or hardness. **Key Advantages Summary:** 1. **Exceptional Impact Toughness**: Superior resistance to fracture under shock loading 2. **High Fatigue Strength**: Excellent performance under cyclic loading conditions 3. **Good Wear Resistance**: Adequate abrasion resistance for many applications 4. **Minimal Distortion**: Excellent dimensional stability during heat treatment 5. **Versatile Performance**: Suitable for a wide range of demanding applications For toolmakers, engineers, and manufacturers facing challenges with tool failure due to impact, shock loading, or high-stress concentrations, S7 Alloy provides a reliable, proven solution. While not intended for applications requiring extreme wear resistance or high-temperature performance, it excels in environments where tools and components must withstand repeated impact without failing catastrophically. When the application demands a tool steel that can absorb extreme punishment without cracking, that maintains its structural integrity under repeated shock loading, and that provides reliable performance in the toughest industrial environments, Carpenter S7 Alloy stands as the engineered solution backed by Carpenter's metallurgical expertise and quality assurance. --- *For specific application recommendations, heat treatment guidelines, or technical assistance, consult with Carpenter Technology's technical services team. Always refer to the latest technical data sheets for current specifications and processing recommendations.* -:- For detailed product information, please contact sales. -: Carpenter S7 Alloy Tool Steel (AISI S7) Specification Dimensions Size： Diameter 20-1000 mm Length <6945 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. -: Carpenter S7 Alloy Tool Steel (AISI S7) Properties -:- For detailed product information, please contact sales. -:

Applications of Carpenter S7 Alloy Tool Steel Tube (AISI S7) -:- For detailed product information, please contact sales. -: Chemical Identifiers Carpenter S7 Alloy Tool Steel Tube (AISI S7) -:- For detailed product information, please contact sales. -:

Packing of Carpenter S7 Alloy Tool Steel Tube (AISI S7) -:- 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 Tube 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 3416 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