ThePipingMart Blog Grades O2 Tool Steel (UNS T31502) – Composition, Properties and Uses

O2 Tool Steel (UNS T31502) – Composition, Properties and Uses

Tool Steel O2

Tool Steel O2 is a type of high-carbon tool steel that is often used in the production of knives, industrial tools, and machine components. UNS T31502 steel is renowned for its excellent strength and durability, making it perfect for use in a variety of industries. O2 Tool Steel, also known by its technical name UNS T31502, is one of the most popular tool steels in the world. It is a versatile material with excellent hardness, wear resistance, and dimensional stability, making it ideal for various applications. This steel is a low-alloy, cold-work tool steel with a high carbon content, allowing it to maintain its edge at elevated temperatures. The composition of O2 Tool Steel consists of tungsten, manganese, chromium, and silicon, which lends it its unique properties. It is important to note that this steel must be properly heat-treated to achieve its full potential. Overall, UNS T31502 offers exceptional performance, durability, and reliability, making it a preferred choice for demanding tooling and manufacturing applications. Here, we will explore the properties of this remarkable material and how it can be applied in various settings.

What Forms of O2 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

O2 Tool Steel Composition

Element Content (%)
Manganese, Mn 1.40-1.80
Carbon, C 0.85-0.95
Silicon, Si 0.5
Chromium, Cr 0.35
Nickel, Ni 0.3
Molybdenum, Mo 0.3
Vanadium, V 0.3
Copper, Cu 0.25
Phosphorus, P 0.03
Sulfur,S 0.03

O2 Tool Steel Physical Properties

Properties Conditions
T (°C) Treatment
Density 7.66 x 1000 kg/m3 25

O2 Tool Steel Mechanical Properties

Properties Conditions
T (°C) Treatment
Poisson’s ratio 0.27-0.30 25
Elastic modulus 27557-30458 ksi 25

O2 Tool Steel Thermal Properties

Properties Conditions
T (°C) Treatment
Thermal expansion 11.2 x 10-6/ºC 20-100

O2 Tool Steel Equivalents

  • ASTM A681
  • DIN 1.2842
  • SAE J437
  • SAE J438
  • UNS T31502
  • AFNOR 90 MV 8
  • UNI 88 Mn V 8 KU
  • B.S. Bo 2
  • FED QQ-T-570

O2 Tool Steel Uses

O2 Tool Steel is an incredibly versatile material that can be used for a wide range of applications. It can be employed for making cutting tools such as knives or saw blades and components for industrial machines such as drill bits and chisels. The unique properties of this type of steel make it ideal for these types of applications, which require strength and durability.

O2 Tool Steel Uses in Industries

Automotive Industry

One of the most common uses for O2 tool steel is in the automotive industry. This type of steel is used to make a variety of components, such as gears, shafts, and bearings. Its high strength and wear resistance make it ideal for use in high-stress applications within vehicles.

Aerospace Industry

O2 tool steel is also widely used in the aerospace industry due to its ability to withstand extreme temperatures and high-stress levels. It is commonly used to make parts for aircraft engines, landing gear, and other critical components.

Oil and Gas Industry

The oil and gas industry also relies on O2 tool steel for various applications, such as drill bits, valves, and pumps. Its resistance to corrosion and ability to maintain strength at high temperatures make it a valuable material in this sector.

Construction Industry

O2 tool steel is commonly used in the construction industry for making structural components such as beams, columns, and support structures due to its high strength-to-weight ratio. Due to its durability under heavy loads, it is also used in machinery for construction purposes, like cranes or excavators.

O2 Tool Steel Corrosion Resistance

Tool Steel O2 has very good corrosion resistance due to its high chromium content. This means that when exposed to water or other corrosive elements, the steel will not rust or corrode easily. This makes it perfect for use in wet environments, where other types of steel may not withstand the conditions.

O2 Tool Steel Heat Resistance and Heat Treatment

Tool Steel O2 has excellent heat resistance because it contains higher levels of carbon than other steels. This makes it ideal for use in high-temperature environments where other steels may not survive the heat. Furthermore, this type of steel can be heat-treated to further increase its already impressive heat resistance qualities. After undergoing heat treatment, the material will become even harder and more durable than before.

O2 Tool Steel Machinability

Tool Steel O2 is also easy to work with because it has relatively good machinability compared to other steels. This makes it possible to cut and shape the material into any desired shape with relative ease using standard tools such as drill bits and milling machines. Moreover, this type of steel can be welded without too much difficulty as well, allowing you to create complex shapes if needed.


Tool Steel O2 is an extremely versatile material that offers exceptional strength and durability in a wide range of applications. Its excellent corrosion resistance makes it perfect for wet environments, while its high carbon content gives it superior heat resistance capabilities that are further enhanced by heat treatment processes if needed. Furthermore, its good machinability makes it easy to work with using standard tools or welding machines if necessary. All these qualities make Tool Steel O2 an ideal choice for those looking for a strong yet malleable metal that can withstand almost anything thrown at it!

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