ThePipingMart Blog Grades EN31 Die Steel – Composition, Properties, and Uses

EN31 Die Steel – Composition, Properties, and Uses

Properties, Composition, and Uses of Die Steel EN31

Die steel has proven to be incredibly versatile in the manufacturing industry. It is widely used in the production of cars, ships, aircraft, and other machinery components. One type of die steel that is often used is EN31. Let’s take a closer look at this material and explore its composition, properties, uses, and more.

EN31 Die Steel Composition

Die steel EN31 contains 0.95% Carbon, 1% Manganese, 0.35% Silicon, 1% Chromium, and 0.15-0.45% Molybdenum as its major components.

Carbon 0.90-1.20% 0.30-0.75%
Chromium 1.00-1.60% 0.050% max
Silicon 0.10-0.35% 0.050% max

EN31 Die Steel Chemical Properties

EN31 steel is a high-carbon alloy steel that is typically used in engineering applications like gears and shafts due to its impressive mechanical properties. It contains carbon, manganese, sulfur, silicon, and phosphorus, making it highly durable and able to retain its shape in extreme temperatures. EN31 also consists of chromium which enhances its wear resistance as well as toughness. Its design offers excellent machinability meaning it can be drilled or cut into various shapes without losing any of its properties. Its resistance to high stress was one of the main reasons it was chosen for aerospace applications. Overall, EN31 steel is a superior material for engineering projects due to its combination of formability and strength.

EN31 Die Steel Mechanical Properties

EN31 Steel is a high-carbon alloy steel which achieves its unique properties through a combination of heat treatment, quenching, and tempering. It boasts excellent wear resistance and high compressive strength, making it ideal for a variety of applications such as industrial gears, shafts, and bearing races. In addition to its mechanical characteristics, EN31 Steel has excellent machinability and can be cut in non-heat treated conditions or after annealing. The material also offers good ductility and shock absorbency, further expanding the range of uses for it across multiple industries. With its combination of mechanical properties and low cost, EN31 Steel is incredibly versatile and a great choice for many machinical applications.



Tensile Strength

750 N/mm²

Yield Stress

450 N/mm²

Reduction of Area




Modulus of elasticity

215 000 N/mm²


7.8 Kg/m3


63 HRC

EN31 Die Steel Thermal Properties




Thermal expansion coefficient (@ 23-280°C/73.4- 36°F, annealed)

11.9 µm/m°C

6.61 µin/in°F

Thermal conductivity (typical steel)

46.6 W/mk

323 BTU in/hr.ft².°F

EN31 Die Steel Physical Properties

This alloy has a hardness ranging from 40 HRC to 60 HRC with a tensile strength ranging from 400 N/mm2 to 500 N/mm2. It has great wear resistance along with good machinability and strength, making it an ideal choice for many applications.







Mn Si Cr S P Mg

Die Steel EN31


0.52 0.22 1.3 0.05 0.05 –




EN31 Die Steel Equivalent

  • BRITISH BS 970:1991 535A99
  • BRITISH BS 970:1955 EN31
  • SWEDISH SS 2258
  • AMERICAN SAE 52100

EN31 Die Steel Uses

Die Steel EN31 is a versatile metal that can be used in a variety of industrial and commercial applications. It is highly wear-resistant with excellent shock resistance and toughness, making it an ideal material for cutting, shaping, and forming dies. EN31 steel is also easily machinable, which allows for loads of precision when creating intricate components. Even parts subjected to higher levels of stress and temperature, like punches, in automotive compression molding and presses for forging applications, can be successfully taken on by EN31 steels. As such, the precious alloy has widely been utilized in crafting parts related to car engines, bearings manufacturing, bullet shells, and machine tools too.

Heat Resistance & Corrosion Resistance

Die steel EN31 also offers excellent heat resistance as it can withstand temperatures up to 1000°C without any issues. In terms of corrosion resistance, this alloy does not corrode easily even when exposed to extremely corrosive environments like acidic solutions or chemical solvents, making it suitable for use in many industries, such as automotive and aerospace engineering, where corrosion protection is essential.

Machining & Heat Treatment

Die Steel EN31 can be machined using conventional methods like turning or milling but should be done with care as it is prone to work hardening due to its high hardness levels, which can result in tool breakage if not handled properly. Furthermore, this alloy requires heat treatment before use in order to achieve its maximum strength and hardness potentials like quenching and tempering at 860°C followed by oil cooling for best results.


In conclusion, Die Steel EN31 offers great wear resistance along with good machinability and strength, making it an ideal choice for many applications such as automotive and aerospace engineering, where corrosion protection is essential due to its excellent heat resistance capabilities at temperatures up to 1000°C as well as being resistant against corrosion in highly corrosive environments like acidic solutions or chemical solvents. It also requires heat treatment before use in order to achieve maximum strength levels but can be easily machined using conventional tools once treated properly. All these factors combined make Die Steel EN31 an ideal material for various projects requiring die steels!

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