Peeled Round Bars / Tool Steel
AISI S7
Shock-Resisting Tool Steel
Material Overview
AISI S7 - Shock-Resisting Tool Steel
Material Type
Type: Air-hardening shock-resistant tool steel
Key Benefit: Exceptional impact strength combined with high hardness
Key Features
- Impact Strength: Exceptional resistance to shock loading
- Hardenability: Good air-hardening characteristics
- Dimensional Stability: Minimal distortion during heat treatment
- Toughness: Retains toughness at high hardness levels
Mechanical Properties
| Typical Hardness: | 54-56 HRC |
| Impact Strength: | Very High (Charpy) |
| Wear Resistance: | Good |
| Toughness: | Exceptional |
Applications
- Punches and chisels for heavy-duty work
- Hammers and impact tools
- Cold-work forming dies
- Shear blades and cutting tools
- Pneumatic tooling components
- Forging dies and mandrels
- Heavy-duty springs
Advantages
- Shock Resistance: Best in class for impact applications
- Air Hardening: Minimal distortion, no quench cracking
- Toughness + Hardness: Unique combination of properties
- Dimensional Stability: Excellent for precision tooling
- Versatility: Suitable for wide range of tooling applications
Heat Treatment
- Hardening: 925-955°C, air cool (air-hardening)
- Tempering: 205-650°C (depending on desired hardness)
- Annealing: 870-900°C, furnace cool slowly
- Stress Relief: 650-675°C after rough machining
Processing Characteristics
- Machinability: Moderate - best machined in annealed condition
- Grinding: Good grinding characteristics
- Welding: Not recommended - use for repair only with proper procedure
- EDM: Excellent for electrical discharge machining
Design Considerations
- Ideal for applications involving repeated impact or shock loading
- Air hardening eliminates quench cracking risk
- Excellent for large sections requiring through-hardening
- Maintains toughness even at high hardness levels
- Good choice when dimensional stability is critical