Grade S7
Grade S7 is a premium shock-resistant tool steel known for combining extreme toughness, high impact strength, and excellent hardenability.
It is one of the most widely used steels in the S-series and is often preferred for applications where tools must withstand repeated heavy blows or severe shock loading.
S7 offers a unique balance: it can be hardened to high hardness levels (54–60 HRC) while still retaining superb toughness, giving it a clear advantage over many other tool steels such as S1, O1, or even D2 in shock-heavy operations.
Key Properties of S7 Tool Steel
1. Exceptional Shock Resistance (Superior to S1)
S7 is engineered for intense impact applications, maintaining integrity without cracking or chipping.
Perfect for:
a. hammers
b. punches
c. industrial chisels
d. air-tool components
2. High Hardness with Toughness
Unlike many tool steels, S7 can be hardened up to 60 HRC while still remaining highly ductile. This makes it one of the best steels for heavy-duty impact + wear combined applications.3. Air-Hardening Steel
S7 is an air-hardening grade, which helps prevent distortion and warping during heat treatment—ideal for close-tolerance tools.4. Excellent Wear Resistance
Although not as high-wear-resistant as D2, S7 still delivers solid abrasion resistance, making it suitable for cutting, forming, and shearing tools that undergo shock.5. Good Softening Resistance
S7 maintains hardness at moderately elevated temperatures, making it useful for hot-work applications like forging inserts and dies.6. Good Machinability in Annealed Condition
Easy to machine, drill, and mill before hardening, which lowers production time.Common Applications of S7
Grade S7 is widely used in industries such as forging, automotive, metal forming, construction, and tooling. Typical applications include:
1. Punches, dies & stamping tools
2. Air chisels & pneumatic tool parts
3. Cold-work tools exposed to shock
4. Shear blades for heavy-impact cutting
5. Jackhammer bits
6. Riveting and punching tools
7. Forming dies
8. Hammers & impact tools
9. Plastic mold dies requiring toughness