ThePipingMart Blog Grades S6 Tool Steel (UNS T41906) – Composition, Properties and Uses

S6 Tool Steel (UNS T41906) – Composition, Properties and Uses

Tool Steel S6

Tool steel is an essential component of many businesses. It’s used for the creation of tools and machines, as well as for manufacturing products. One type of tool steel gaining popularity is Tool Steel S6, a special air-hardening alloy tool steel. Regarding tool steel, S6 Tool Steel, also known as UNS T41906 or SAE-AISI S6 steel, is a popular choice due to its unique composition and properties. This type of tool steel contains high levels of carbon and chromium, which give it excellent hardness and wear resistance. In addition, its high silicon content increases its resistance to heat and oxidation. S6 Tool Steel is often used in applications where toughness and durability are crucial, such as cutting tools, stamping dies, and machine components. Overall, if you’re looking for reliable and high-performing tool steel, S6 Tool Steel is worth considering. Let’s take a look at what makes this material so unique and why it has grown in popularity over the years.

What Forms of S6 Tool Steel is Available at Piping Mart?

  • Nut
  • Bar
  • Bolt
  • Pipe
  • Screw
  • Tubing
  • Valves
  • Washers
  • Flanges
  • Fasteners
  • Electrodes
  • Stud Bolts
  • Sheet Plates
  • Pipe Fittings
  • Forged Fitting
  • Instrumentation Fittings

S6 Tool Steel Composition

Content (%)
Iron, Fe
Carbon, C
Manganese, Mn
Silicon, Si
Chromium, Cr
Molybdenum, Mo
Vanadium, V
Copper, Cu
Phosphorus, P
Sulfur, S

S6 Tool Steel Physical Properties

Properties Metric Imperial
Density 7.75 g/cc 0.280 lb/in3
Melting point 1432°C 2610°F

S6 Tool Steel Mechanical Properties

Properties Conditions
T (°C) Treatment
Poisson’s ratio 0.27-0.30 25
Elastic modulus 190-210 GPa 25

S6 Tool Steel Thermal Properties

Properties Conditions
T (°C) Treatment
Thermal expansion 12.6 x 10-6/ºC 20-425

S6 Tool Steel Equivalents

  • ASTM A681
  • FED QQ-T-570
  • UNS T41906

S6 Tool Steel Uses

S6 Tool Steel offers good wear resistance and toughness, making it well-suited for applications that require high-impact strength. It’s often used to make machine parts such as punches, dies, shear blades, chisels, and cold-forming tools. It can also be used to make parts like shafts, couplings, gears, pins, and studs that are subjected to heavy loads or wear and tear.

S6 Tool Steel Uses in Industries

Automotive Industry

S6 tool steel is commonly used in the automotive industry for components such as gears, shafts, and bearings. Its high strength and wear resistance make it ideal for these applications and its ability to withstand high temperatures and pressure.

Aerospace Industry

In aerospace, S6 tool steel is used for critical parts in aircraft engines and turbines. Its high toughness and fatigue resistance make it suitable for withstanding extreme conditions and heavy loads.

Oil and Gas Industry

S6 tool steel is also widely used in oil and gas for drilling equipment, valves, and pumps. Its corrosion resistance and ability to maintain its properties at high temperatures make it a popular choice for these applications.

Medical Industry

Due to its biocompatibility and corrosion resistance, S6 tool steel is used in medical instruments such as surgical blades, dental tools, and orthopedic implants. Its high strength also makes it suitable for these precision instruments.

Tooling Industry

As the name suggests, S6 tool steel is commonly used in the tooling industry for cutting tools such as drills, saws, and dies. Its hardness and wear resistance keep these tools sharp even when working with tough materials.

Construction Industry

Due to its high strength and durability, S6 tool steel is used for various structural components such as bolts, nuts, and fasteners. It can also be found in machinery used on construction sites due to its ability to withstand heavy loads and harsh environments.

S6 Tool Steel Corrosion Resistance

Tool Steel S6 is highly resistant to corrosion because of its high chromium content. This makes it ideal for applications that require chemical resistance or protection against salt water or other harsh environments. It can also withstand temperatures up to 600ºF (316ºC) without significant loss in corrosion resistance properties.

S6 Tool Steel Heat Treatment

Tool Steel S6 can be hardened by heating it in an oven at temperatures between 1450°F (788°C) and 1550°F (843°C). After heating for about one hour per inch (25mm) of thickness at a temperature above 1475°F (802°C), the material should be quenched rapidly in oil or water to cool quickly enough to prevent softening from taking place on the surface or near the surface of the material.   Heat-treating Tool Steel S6 also produces excellent results when done correctly; however, if not done properly, it can lead to cracking due to stresses induced during the cooling process, so it should only be done by experienced professionals familiar with the process who understand how to properly heat treat tool steel materials safely and effectively.

S6 Tool Steel Machining

Tool Steel S6 is relatively easy compared to other types of tool steels due to its low carbon content, which allows for smoother cutting operations without too much stress on your machining equipment or tools when compared with higher carbon content steels like D2 or H13. However, you should still use a high-speed steel cutter when machining this grade due to its high hardness levels after heat treatment.


In summary, Tool Steel S6 is a versatile air-hardening tool steel which offers excellent wear resistance, corrosion resistance, toughness, heat treatability, machinability and affordability, making it an ideal choice for many applications across various industries. Whether you need parts made from this material that require high impact strength, chemical resistance, and saltwater protection or just want something more affordable than other grades of tool steel, look no further than Tool Steel S6! Intended Audience: Engineers and industrial manufacturers looking for information on Tool Steel S6.

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