S7 Tool & Die Steel Round Bars

A comprehensive overview of S7 tool and die steel round bars, covering chemical composition, physical and mechanical properties, applications, processing methods, standards, and surface finish considerations.

S7 tool & die steel round bars offer exceptional toughness and impact resistance, making them ideal for cold and hot forging dies, extrusion dies, and other high-stress applications requiring superior durability and wear resistance.

Chemical Composition:

Physical Properties:

• Density: 7.83 g/cm³
• Melting Point: Approximately 1450°C (2640°F)
• Thermal Conductivity: 21.6 W/(m·K) at 100°C

Mechanical Properties:

• Tensile Strength: 1925 MPa (280 ksi)
• Yield Strength (0.2% Offset): 1620 MPa (235 ksi)
• Elongation at Break: 10%
• Hardness, Rockwell C: 52-58 HRC

Applications: 

S7 tool steel is commonly used in applications requiring high impact resistance, such as:

• Cold and hot forging dies
• Extrusion dies
• Shear blades
• Stamping dies
• Injection mold tools

Processing:

• Forging: Typically done at temperatures between 980-1140°C (1800-2100°F), followed by air cooling or quenching.
• Heat Treatment: Annealing, normalizing, hardening, and tempering processes are commonly employed to achieve desired hardness and toughness.
• Machining: S7 steel can be machined using conventional methods, though it requires high-speed steel tooling due to its hardness.

Standards: 

S7 tool steel conforms to various international standards such as ASTM A681 and AISI S7.

Surface Finish: 

Surface finishes for S7 tool steel round bars are typically achieved through grinding, polishing, or shot blasting, depending on the application requirements.