Sichuan Liaofu Special Steel Company is one of the most experienced manufacturers and suppliers of s7 tool steel bar stock in China. With over 20 years' experience, our factory offer high quality products made in China with competitive price. Welcome to contact us for wholesale service.
What is S7 Tool Steel?
In tool steel standardASTM A681, shock-resisting tool steels are designated as group S steels according to the AISI classification system. S1, S2, S5, S6, and S7 are the types of shock-resisting tool steels. AISI S7 tool steel is a shock-resistant air hardening steel. AISI S7 steel has exceptional impact properties plus the highest hardenability of shock resisting grades of tool steel. Steel S7 also possesses good softening resistance at high temperatures which gives it hot work capabilities. Since S7 steel hardens in air, it is also safe and stable in heat treatment.
AISI S7 tools steel has an unusual combination of properties, making it suitable for an extremely wide range of tool and die work – where shock-resistance, medium hot-work properties, or ease of machining and heat-treatment are most important.
Sichuan Liaofu Special Steel is a professional supplier of S7 tool steel materials as below range and technical requirements. We could supply AISI s7 Round Bar, S7 Drill Rod, S7 Rectangular Bar, S7 Flat Bar, S7 Square Bar and Plate. Welcome to contact us for more information and ask for a quick quote anytime.
Supply Range of AISIS7 Tool Steel:
- Diameter 8mm – 1000mm
- Thickness 2mm –600mm x width 200mm – 2200mm
- Surface Finish: Black, Rough Machined, Turned or as per given requirements
- Process: Hot rolled, Forged, Cold drawn etc
Specification of S7 Tool Steel
1. Relevant Steel Specification for S7 Tool Steel
| Country | USA | German |
| Standard | ASTM A681 | DIN EN ISO 4957 |
| Grades | S7/T41907 | 1.2355/50CrMoV13-15 |
2. AISI S7 Steel Chemical Composition and Steel Equivalents
| ASTM A681-2008 | C | Si | Mn | P | S | Cr | V | Mo | ||||||
| S7/T41907 | 0.45 | 0.55 | 0.20 | 1.00 | 0.20 | 0.90 | 0.03 | 0.03 | 3.00 | 3.50 | – | 0.35 | 1.30 | 1.80 |
| DIN ISO 4957 | C | Si | Mn | P | S | Cr | V | Mo | ||||||
| 1.2355/50CrMoV13-15 | 0.45 | 0.55 | 0.20 | 0.80 | 0.50 | 0.90 | 0.03 | 0.02 | 3.00 | 3.50 | 0.15 | 0.35 | 1.30 | 1.70 |
3. S7 Tool Steel Mechanical Properties
Heat treatment Related
Annealing of AISI S7 Tool steel
Slowly heated the S7 tool steel to 800-810 ℃(1472-1490℉) and allow enough times, let the steel to be thoroughly heated, Then cool slowly in the furnace. The S7 tool steel will get MAX 250 HB (Brinell hardness).
Hardening of AISI S7 tool steel
S7 steels should be uniformly heated to 650°C (1202°F) until completely heated through. Then rapid increase temperature to 900-950 ℃(1652-1742℉) quenched in oil.
Tempering of AISI S7 tool steel
Tempering of S7 steels at the required tempering temperature, Soak well at the selected temperature and soak for at least one hour per 25mm of total thickness. Get Rockwell C hardness of 49 to 61.
Temperature [℃] 100 150 200 250 300 400
Hardness [HRc] 61-59 58-56 56-54 55-53 56-55 52-49
4.Tool Steel S7 Physical Properties
| Elastic Modulus | 207GPa | |
| Density | 7.83 g/cm³ | |
| Thermal Conductivity | W/m- °K | Cal/cm-s-°C |
| at 95°C | 28.5 | 0.068 |
| Thermal Properties | ||
| Critical Temperature: | 800c | |
| CTE, linear 20°C | 12.59µm/m- °C | |
| CTE, linear 250°C | 13.33µm/m- °C | |
| CTE,linear 500°C | 14.27µm/m- °C | |
| Transformation Temperature | 785 °C | |
5. Forging of AISI Steel S7
Preheat 1200°-1300°F. Forge at 2000°-2050°F. Stop at 1700°F and cool slowly.
Contact US
FAQ
Q: Can I substitute S7 tool steel for D2 or A2?
A: Yes, if your primary concern is shock resistance. S7 is a shock-resisting steel with superior toughness compared to D2 (which is wear-resistant but brittle) and A2 (which is air-hardening but less tough). S7 is ideal for chipping-prone dies and punches.
Q: Why do some machinists experience cracking after wire EDM cutting S7?
A: S7 has high hardenability and contains significant carbon. If the material is not properly tempered after hardening, the residual stress can cause cracking during wire EDM. Ensure the part is fully tempered and stress-relieved before EDM machining.
Q: Is S7 suitable for hot work applications?
A: It is suitable for medium hot work. S7 retains good softening resistance at high temperatures and can be used for hot punching or forging dies where shock is present. However, for continuous high-temperature operations, H13 is usually a better choice.
Q: Can S7 be quenched in air instead of oil?
A: Yes, S7 hardens in still air, which minimizes distortion. However, for larger cross-sections (over 65mm), an oil quench is recommended to ensure full through-hardening. For small tools, air cooling is usually sufficient and safer for maintaining dimensional stability.
Q: Do you supply S7 in the annealed condition?
A: Yes, the base material is supplied fully annealed from our in-house production base, with a maximum Brinell hardness of 250 HB. This makes it easy to machine, drill, and form your tool before the final heat treatment.
Hot Tags: s7 tool steel bar stock, China, manufacturers, suppliers, factory, Maraging Steel C300 Round Bar, Engine Valve Steel bar, St52 Carbon Steel Hollow Bar, S7 Tool Steel Bar Stock, 4J29 Precision Alloy Steel bar, 1 2714 SKT4 L6 Alloy Die Steel Bar