S7 Steel: Unmatched Reliability for Demanding Applications

S7 steel provides exceptional shock resistance, dimensional stability, and versatility to meet the most demanding requirements.

Get Superior S7 material from Aobo Steel at Competitive Prices

S7 steel is an American ASTM standard S7 heavy-duty and medium-carbon alloy tool steel. Its high chromium content offers good tempering resistance and resistance to high-temperature oxidation.

Aobo Steel is a professional supplier, providing over 20 types of steel in the tool steel product sector. We are not just a material supplier but also a service supplier.. Our top-quality technology and customer service enable small and medium-sized factories worldwide to conveniently obtain reliable quality material at the best price.

Additional information: When looking for an S7 material equivalent, 1.2355 is often considered a close match.

Application Scenarios

Cold Work Tools: Includes shear blades, punches, chisels, swaging dies, and gripper dies, all needing high impact resistance.
Molding Applications: Used in plastic injection molds and inserts, ensuring precision and durability.
Die Casting: Suitable for aluminum and zinc casting dies, offering good thermal fatigue resistance.
Hot Work Tools: Applied in environments up to 1000°F, such as forging dies and aerospace components.

Why choose Aobo Steel as your supplier

We offer over 100 types of steel, including tool steel, alloy steel, stainless steel, alloy structural steel, and carbon steel.

We provide free cutting services.

With over 40 processing suppliers surrounding us, we have the capacity to deliver more than 2,000 tons of steel per month.

S7 tool steel Properties

What is S7 steel? Here we understand it from data, including composition, properties, heat treatment, etc.

S7 Steel Composition

Element	Carbon (C)	Manganese (Mn)	Silicon (Si)	Cromo (Cr)	Molibdeno (Mo)
Content (%)	0.45-0.55	0.20-0.80	0.20-1.00	3.00-3.50	1.30-1.80

Heat treatment

Annealing Specification: For the best softening effect, the annealing temperature is 810–830°C, and the cooling rate is 15–30°C/h.

Quenching and Tempering Specification: The quenching temperature is 850–880°C, and the tempering temperature is 550°C.

Physical property

Property	Value
Hardness (after heat treatment)	55-60 HRC
Tensile Strength (UTS)	670-2030 MPa (97-290 x 10^3 psi)
Elastic Modulus	190 GPa (28 x 10^6 psi)
Poisson’s Ratio	0.29
Shear Modulus	74 GPa (11 x 10^6 psi)
Impact Strength (Charpy V-notch)	10-12.5 ft-lb (13.6-16.9 J at various temperatures)

The benefits

Exceptional Shock Resistance and Impact Toughness

Air-Hardening Capability with Minimal Distortion

Easy Machinability in Annealed Condition

Good Dimensional Stability

Adequate Wear Resistance

Resistance to Thermal Fatigue in Hot Work Conditions

S7 tool steel vs. other steels

In production practice, S7 and 4140 steel are always difficult to choose; S7 is a hot work tool steel, and 4140 is a low alloy steel. We compare their data to give users a reference. S7 tool steel vs 4140:

Property	S7 Tool Steel	4140 Steel
Tipo	Shock-resisting tool steel	Chromium-molybdenum alloy steel
Composition	C: 0.50%, Cr: 3.25%, Mo: 1.10%, V: 0.30%	C: 0.40%, Cr: 0.95%, Mo: 0.20%
Hardness (HRC)	55-60	50-55
Strength	High (tensile strength ~240 KSI)	High (tensile strength ~140-160 KSI)
Toughness	Excellent (high impact resistance)	Good
Wear Resistance	Good	Good
Heat Resistance	Good (up to 1000°F)	Fair (up to 600°F)
Machinability	Good (in annealed condition)	Good (in annealed condition)
Cost	Higher	Lower
Typical Uses	Punches, dies, shear blades	Gears, shafts, structural parts

Take the Next Step Toward Better Performance

Don’t wait for another material failure to halt your progress. S7 steel offers the strength, reliability, and versatility your manufacturing projects demand.

The AISI S7 Equivalent: DIN 1.2355

In the German steel standard, S7 steel is equivalent to DIN 1.2355. They have similar chemical compositions and mechanical properties, and can be substituted for each other.

1.2355 steel Chemical composition

Carbon (C)	Cromo (Cr)	Molibdeno (Mo)	Vanadium (V)	Manganese (Mn)	Silicon (Si)	Phosphorus (P)	Sulfur (S)
0.45 – 0.55	3.00 – 3.50	1.30 – 1.70	0.15 – 0.35	0.50 – 0.90	0.20 – 0.80	max 0.030	max 0.020

1.2355 tool steel Physical Property

Physical Property	Value	Units	Notes
Density	7.76	g/cm³	Approximate value.
Coefficient of Thermal Expansion (CTE)	12.6	μm/m·K (20-200 °C)	Varies with temperature.
Coefficient of Thermal Expansion (CTE)	13.3	μm/m·K (20-425 °C)	Varies with temperature.
Coefficient of Thermal Expansion (CTE)	13.7	μm/m·K (20-500 °C)	Varies with temperature.
Modulus of Elasticity	207	GPa	Approximate value.