S7 Tool Steel Rockwell Hardness Chart

S7 tool steel is commonly supplied in the annealed condition at about 187–223 HB, with some suppliers allowing an upper annealed hardness of about 230 HB. After hardening and tempering, S7 is usually used around 54–58 HRC. For many punches, dies, chisels, shear blades, and shock-loaded tools, 56–58 HRC is a practical working range because it gives useful strength while preserving S7’s main advantage: shock resistance.

S7 can reach about 59–61 HRC after quenching, but this is not normally the best working condition. For real-world tooling use, the final Rockwell hardness should be selected based on the tool’s failure risk. If the tool wears or deforms too quickly, higher hardness may help. If the tool chips, cracks, or breaks under impact, a lower hardness range is usually safer.

This page is designed as a quick hardness reference for S7 tool steel. For detailed hardness selection logic, toughness balance, and comparison with other tool steels, see our S7 Tool Steel Hardness guide.

S7 Tool Steel Rockwell Hardness Chart

The table below summarizes typical S7 tool steel hardness values in annealed, as-quenched, tempered, and application-based conditions. These values are useful for material selection, purchase discussion, and heat-treatment planning, but final hardness should always be confirmed by actual testing.

For S7 tool steel, the highest HRC value is not always the best target. A tool hardened to near 60 HRC may exhibit high edge hardness but may lose some of the impact toughness that makes S7 useful. For repeated shock loading, a slightly lower working hardness often yields a longer service life.

Aobo Steel can supply S7 round bar, flat bar, and plate in bulk. We support hardness inspection, chemical composition verification, ultrasonic testing when required, and MTC documentation for each order. Contact [email protected].

S7 Annealed Hardness Reference

S7 tool steel is normally supplied in the annealed condition because the material must be machinable before final hardening. In this condition, Brinell hardness is more useful than Rockwell C hardness.

The common annealed hardness range is 187–223 HB. Some references use 200–225 HBW, and about 230 HB is often treated as an upper reference limit. These ranges all describe soft, machinable S7 before final heat treatment.

Annealed S7 should not be judged as “too soft” simply because it is below its final working hardness. The annealed condition is the correct supply condition for cutting, milling, drilling, grinding, and preparing the tool before heat treatment.

Aobo Steel supplies S7 tool steel in an annealed condition for machining, stockholding, and later heat treatment by the buyer or the buyer’s heat-treatment facility.

S7 Rockwell Hardness After Hardening and Tempering

After hardening, S7 can reach about 59–61 HRC in the as-quenched condition. This is a heat-treatment stage, not the normal service condition. The steel must be tempered to reduce internal stress and adjust the final balance between hardness and toughness.

For most practical tooling applications, S7 is used around 54–58 HRC. The 56–58 HRC range is often selected when the tool requires impact resistance, compressive strength, and moderate wear resistance simultaneously.

The final hardness depends on austenitizing temperature, quenching method, tempering temperature, section size, and service requirement. A hardness value on paper should always be matched to the tool’s actual working conditions.

S7 Hardness by Application

S7 hardness should be selected according to how the tool is expected to fail. Tools exposed to heavy impacts usually require greater toughness. Tools exposed to wear, cutting, or deformation may need a higher hardness.

For most S7 tooling, 56–58 HRC is the practical center. If the tool is cracking, increasing hardness usually makes the problem worse. If the tool is deforming or wearing too quickly, higher hardness may help, but a more wear-resistant grade may also be a better solution.

S7 Hardness Conversion: HRC to HB

Annealed S7 is usually specified in Brinell hardness. Hardened and tempered S7 is usually specified in Rockwell C hardness.

The table below gives approximate HRC-to-HB references for hardened steel. These values are conversions only. They should not replace actual hardness testing when a purchase order, drawing, or inspection report requires a specific scale.

For annealed S7, with hardness around 187–223 HB, Rockwell C conversion is less reliable and less useful. In this soft condition, HB or HBW should be used as the main hardness reference.

Aobo Steel supplies S7 tool steel as raw material in an annealed condition. This condition is suitable for machining, further processing, and final heat treatment by the buyer or the buyer’s heat-treatment facility.

For bulk S7 tool steel orders, Aobo Steel can supply round bar, flat bar, and plate, with chemical composition inspection, hardness testing, and ultrasonic testing when required, and provide MTC documentation for each order.

Aobo Steel does not provide final hardening and tempering service. This article is provided as technical support for buyers who need to understand S7 hardness ranges, working-hardness selection, and the basic influence of heat treatment before purchasing raw material.

For S7 tool steel price, size availability, and bulk supply details, contact [email protected]. Or you can view our S7 tool steel product page.