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Tool Steel CNC Machining

Tool steels are metal alloys with extremely high hardness, stiffness and abrasion resistance. Suitable for producing industrial devices.

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Tool Steel CNC Machining

Tool steel is any one of the different carbon and alloy steels that are especially well-suited to be made into tooling, such as cutting devices, dies, hand tools, blades, and others. Tool steel’s viability originates from its unique hardness, resistance to abrasion and deformation, and capability to hold a reducing side at elevated temperature levels.

Consequently, tool steels are matched for usage in shaping other products, such as cutting, machining, stamping, or creating.

A2 Steel: A2 steel is a cold-work tool steel with good cutting performance and toughness. It is used for manufacturing cooling molds, die holders, and extrusion dies.

D2 Steel: D2 steel is a high-carbon, high-chromium cold-work tool steel with excellent hardness, wear resistance, and cutting performance. It is suitable for making cutting tools, stamping dies, and cold-work molds.

O1 Steel: O1 steel is a classic oil-hardening cold-work tool steel with good hardness, wear resistance, and cutting performance. It is suitable for making cutting tools, molds, and die holders.

H13 Steel: H13 steel is a hot-work tool steel with good high-temperature strength and heat resistance. It is used to make hot-work molds, die-casting molds, and extrusion dies.

S7 Steel: S7 steel is a cold-work tool steel with good impact toughness and wear resistance. It is used for making impact dies, die holders, and extrusion dies.

All tool steels mentioned above can be heat treated to improve their hardness and strength.

Tool Steel Subtypes

Ultimate tensile strengthYield strengthYoung’s modulus (modulus of elasticity)Elongation at breakCorrosion resistanceMagnetismWeldabilityApplication
Tool Steel A2670 – 710 MPa345 – 350 MPa190 GPa21 %PoorMagneticModerateCutting & Shearing tools Cold-forming dies Die casting and molding diesLearn More
Tool steel A3700 MPa340 MPa190 GPa21%PoorMagneticPoorCold forging & heading dies Cold forging dies Shear blades Knurling toolsLearn More
Tool steel D2758 – 860 MPa420 – 470 MPa190 GPa16%PoorMagneticPoorHot forging tools and dies Hot extrusion tools and dies Cold forming diesLearn More
Tool steel O1640 – 720 MPa400 MPa190 GPa20%PoorMagneticPoorCutting tools Cold-forming dies Shearing tools Die casting and molding diesLearn More
Tool steel S7640 – 670 MPa370 – 380 MPa190 GPa21 – 25 %PoorMagneticPoorCutting tools Hot forging & extrusion tools Cold-forming dies Shearing toolsLearn More
Tool steel H13690 MPa330 MPa190 GPa21%PoorMagneticPoorExtrusion & pressure dies Forging & stamping dies Hot shear bladesLearn More

Tool Steel CNC Machining Surface Finishes

Tool Steel CNC Machining Gallery

Cost-saving Design Tips

To lower costs, restrict the number of part setups, the number of inspection dimensions or tight tolerances, and deep pockets with small radii.


There are six tool steels: water-hardening, cold-work, shock-resistant, high-speed, hot-work, and special purpose. The group selection choice depends on cost, working temperature, required surface hardness, strength, shock resistance, and toughness requirements.

The more severe the service condition (higher temperature, abrasiveness, corrosiveness, loading), the higher the alloy content and consequent amount of carbides required for the tool steel.

Tool steels are used for cutting, pressing, extruding, and coining of metals and other materials. Their use in tooling is essential; injection molds for example require tool steels for their resistance to abrasion- an important criterion for mold durability which enables hundreds of thousands of moldings operations over its lifetime.

Yes, heat treatment is often used to optimize the hardness and wear resistance of tool steel components.

A2, D2, O1 and S7 are the common tool steels used for CNC machining.

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