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S5 Tool Shock Resisting Steel: Properties, Process, Uses
- John
S5 tool steel combines high toughness with excellent impact resistance, making it perfect for high-stress environments. This article explores its properties, heat treatment, and key industrial applications. Whether you’re looking to enhance product performance or understand the best use cases, this guide provides the insights you need.
What Is S5 Tool Steel?
S5 tool steel is a medium carbon, oil-hardening steel from the “S” series, known for its high impact toughness. It combines silicon-manganese steel properties with the advantages of oil-hardening steel, offering reduced distortion during heat treatment. S5 can be hardened to 62 Rockwell C and is used primarily in high-strength applications such as impact tools, forging dies, and cutting tools. Compared to S7, S5 provides superior toughness and strength, making it a better choice for demanding environments.
SteelPro Group provides S5 tool steel in round bars, flat bars, plates, and custom shapes, tailored to various applications. Our products meet international standards, including ASTM A681, FED QQ-T-570, SAE J437, and SAE J438, ensuring precision and reliability.
What Is S5 Tool Steel Equivalent To?
S5 tool steel is equivalent to the following grades in various standards:
- UNS: T41905
- DIN: 1.2357
- JIS: SKS3
- BS: 230M07
Chemical Composition of S5 Tool Steel
S5 tool steel’s composition balances strength, toughness, and wear resistance. Key elements like carbon, chromium, and vanadium enhance hardness and durability. The table below lists its chemical makeup.
| Element | Composition (%) |
| Carbon (C) | 0.50 – 0.65 |
| Chromium (Cr) | ≤ 0.35 |
| Iron (Fe) | 95 |
| Manganese (Mn) | 0.8 |
| Molybdenum (Mo) | 0.77 |
| Phosphorus (P) | ≤ 0.030 |
| Silicon (Si) | 2 |
| Sulfur (S) | ≤ 0.030 |
| Vanadium (V) | ≤ 0.35 |
Physical Properties of S5 Tool Steel
The table below summarizes the physical properties of S5 tool steel.
| Property | Metric | Imperial |
| Density | 7.85 g/cm³ | 0.284 lb/in³ |
| CTE, Linear | 11.0 µm/m-°C | 6.11 µin/in-°F |
Mechanical Properties of S5 Tool Steel
The mechanical properties of S5 tool steel reflect its strength, hardness, and toughness. These properties vary with heat treatment conditions. The table below summarizes key mechanical properties of S5 tool steel.
| Property | Metric | Imperial |
| Hardness, Knoop | 548 | 548 |
| Hardness, Rockwell C | 55 – 60 HRC | 55 – 60 HRC |
| Hardness, Vickers | 560 | 560 |
| Tensile Strength (Ultimate) | 965 – 1200 MPa | 140000 – 174000 psi |
| Tensile Strength (Yield) | 690 MPa | 100000 psi |
| Elongation at Break | 9-15% | 15% |
| Bulk Modulus | 160 GPa | 23207 ksi |
| Shear Modulus | 80 GPa | 11603 ksi |
The mechanical properties of S5 tool steel are influenced by heat treatment, primarily due to changes in microstructure.
- Higher quenching temperatures and faster cooling rates produce martensite, increasing hardness and tensile strength but reducing toughness.
- Tempering at specific temperatures reduces hardness, improving ductility and toughness.
- The elongation at break and impact toughness typically decrease with higher hardness.
Heat Treatment of S5 Tool Steel
The heat treatment process is critical in maximizing the performance of S5 tool steel, ensuring optimal hardness, toughness, and wear resistance. At SteelPRO Group, we provide S5 tool steel in a pre-machined or ready-to-use state, allowing our clients to receive material tailored to their specific requirements with minimal post-processing.
Annealing
Heating: Uniformly heat the steel to 1550°F (843°C).
Soak Time: Hold the steel for 1 hour per 25.4mm (1 inch) of thickness to ensure even temperature distribution.
Cooling Process: Cool the steel slowly at 20°F (11°C) per hour until it reaches 1000°F (538°C). Then allow the steel to air cool to room temperature.
Hardness Post-Annealing: After annealing, the hardness should be between 180-220 HB, depending on exact cooling and composition.
Hardening
Preheating: Slowly heat the steel to 1600°F (871°C). For complex or large parts, first preheat to 1200°F (649°C) to reduce thermal stress and cracking risks.
Austenitizing: After preheating, raise the temperature to 1800°F (982°C) for austenitization.
Soak Time: The first 25.4mm (1 inch) of material should be held for 30 minutes, with an additional 15 minutes per 25.4mm of thickness for uniform heating.
Quenching: Quench the steel in oil or air to below 150°F (66°C) to achieve martensitic transformation, ensuring the steel hardens properly.
Tempering
Heating: Uniformly heat the steel to 1100°F (593°C) for tempering.
Soak Time: Hold the steel for 1 hour per 25.4mm (1 inch) of thickness.
Cooling: After tempering, allow the steel to air cool.
Extended Soak (for large sections): For cross-sections greater than 6 inches (152.4mm), soak at tempering temperature for 4-6 hours to minimize internal stresses and enhance the stability of EDM tools post-treatment.
Cryogenic & Low-Temperature Treatment
Cryogenic and low-temperature treatments enhance the performance of S5 tool steel by improving wear resistance, toughness, and dimensional stability. Both treatments occur after hardening and before tempering.
Cryogenic Treatment
Temperature: -80°C to -196°C (-112°F to -320°F)
Time: 24 to 48 hours
Purpose: Converts retained austenite to martensite, improving hardness and wear resistance.
Low-Temperature Treatment
Temperature: -80°C to -120°C (-112°F to -184°F)
Time: 6 to 12 hours
Purpose: Provides stress relief and enhances dimensional stability.
S5 Tool Steel Product Forms
S5 tool steel is available in various forms, including round bars, flat bars, plates, and custom shapes, with typical size ranges tailored to different applications. We ensure strict tolerance control for all our products. If your project requires sizes beyond the standard range, we can accommodate custom dimensions.
| Product Form | Size Range (Metric) | Size Range (Imperial) |
| Round Bars | Diameter: 25mm – 500mm | Diameter: 1″ – 20″ |
| Length: 1000mm – 6000mm | Length: 3′ 3″ – 19′ 8″ | |
| Flat Bars | Thickness: 5mm – 100mm | Thickness: 0.2″ – 4″ |
| Width: 50mm – 500mm | Width: 2″ – 20″ | |
| Length: 1000mm – 6000mm | Length: 3′ 3″ – 19′ 8″ | |
| Plates | Thickness: 5mm – 100mm | Thickness: 0.2″ – 4″ |
| Width: 100mm – 1500mm | Width: 4″ – 59″ | |
| Length: 1000mm – 4000mm | Length: 3′ 3″ – 13′ 1″ | |
| Custom Shapes | Customized to specifications | Customized to specifications |
S5 Tool Steel Applications
S5 tool steel’s combination of hardness, toughness, and wear resistance makes it well-suited for tools and components that experience high stress, impact, and wear. Below are the specific applications where S5 tool steel is commonly used:
- Die-Cutting Tools: Used in cutting and stamping tools for metal and plastic.
- Forging Dies: Ideal for producing dies that shape hot metal in forging processes.
- Plastic Injection Molding Tools: Used in molds and inserts for plastic molding.
- Cold Working Tools: Punches, chisels, and dies for cold forming operations.
- Blades for Metalworking: Knives, shears, and saw blades for cutting metals.
- Thread Cutting Tools: Taps and dies for cutting threads in tough materials.
- Mining Equipment: Components like drilling bits and rock crushers.
- Mold Inserts for High-Pressure Die Casting: Inserts for casting aluminum, zinc, and magnesium alloys.
Tailored Our S5 Tool Steel for Higher Performance
At SteelPro Group, we provide S5 tool steel in round bars, flat bars, plates, and custom shapes, all tailored to your exact specifications. We also offer D2 high-carbon, high-chromium steel plate products. Our services include precision machining, custom sizes, and heat treatments such as hardening and tempering, ensuring optimal performance for your specific applications.
With our expertise and flexible solutions, we help reduce processing time and deliver high-quality, ready-to-use S5 steel for your projects.
