S7 is an air-hardening shock-resistant tool steel, classified under the AISI/SAE tool steel series (S-series) in the United States. Its European equivalent is approximately DIN 1.2355.
Compared to conventional cold work tool steels, S7 stands out for its exceptional impact toughness, while maintaining good wear resistance and dimensional stability during heat treatment. This makes it a popular choice for punches, shear blades, impact tools, hammers, and more.
Moderate Wear Resistance: While not as wear-resistant as high-chromium steels like D2, it offers far better impact and fatigue resistance.
Heat Treatment Stability: Air-hardening minimizes cracking and distortion—ideal for precision parts.
Excellent Machinability: Easy to machine, grind, and polish compared to many other tool steels.
Thanks to its outstanding balance of toughness and wear resistance, S7 is used across a wide range of industries:
High-impact tools (e.g., hydraulic breakers)
Industrial hammers, clamping jaws, and striking tools
Machine components under cyclic or shock loading
If you're working in an environment with heavy impact loads, fatigue stress, or high-precision demands, S7 tool steel is undoubtedly a material worth considering. Its combination of shock resistance, heat treatment stability, and machinability makes it a dependable choice for tooling and engineering applications.