Types of high speed tool steel

High-speed steels exhibit high strength and hardness, but typically exhibit lower toughness than the cold work tool steels. Some, most notably M2 and powder metal M4, are used in cold work applications because of the strength and wear resistance which can be achieved. The lowest alloy grades, M50 and M52 high-speed steels, are properly known as intermediate high-speed steels because of their lower alloy contents.

The cobalt-bearing grades, such as M35 and M42, are known as super high-speed steels because they exhibit enhanced hot hardness. The nominal chemical compositions of the common high-speed and intermediate high-speed tool steels are presented in weight percent below. Relative comparisons of the properties of the steels are presented in the chart on the reverse side. More specific information about the steels may be obtained from the individual data sheets.

Several of the grades are also available in a resulfurized version. Tool steel contains various amounts of tungsten, molybdenum, cobalt and vanadium to increase the heat resistance and durability of the metal. This makes them ideal when used for cutting and drilling.

Tool Steel is divided into these six groups: water-hardening, cold-work , shock-resisting, high-speed, hot-work, and special purpose. The determination of a choice from the group will depend on; the cost effectiveness, working temperature, required surface hardness, strength, shock resistance, and toughness requirement. If there is a more severe demand requirement such as extreme temperature, increased abrasiveness, high corrosion, or excessive loading — higher alloy content and carbides may be required.

Water-hardening class — Named from its essential property of having to be water quenched. This grade of tool steel is essentially plain high carbon steel. It is commonly used because of its low cost. Cold-work classes — Is a group of three tool steels: oil-hardening, air-hardening, and high carbon-chromium. The steels in the group have high hardenability and wear resistance, with average toughness.

Call Today! High Speed Steels are a high-performance subset of tool steels, that are able to machine materials at high cutting speeds, thus the name High Speed Steel. This subset of tool steels is characterized high hardness above 60 Rockwell C and high wear resistance. The primary alloying elements of high speed steels are a combination of carbon, chromium, vanadium, molybdenum or tungsten, and sometimes cobalt. The main reason cobalt is added in some grades of high speed steel is to increase the hot hardness which increases the cutting efficiency of tools when high temperatures are reached.

There are three types of High Speed Steels: Tungsten-type grades i. T1 , Molybdenum-type grades i. M2, M4 , and Cobalt-type grades i. T15, M M2 is a tungsten-molybdenum high speed steel that is characterized by a well-balanced combination of toughness, wear resistance, and red-hardness properties.

M2 is one of the most popular and widely used high speed steels in the world because of its exceptional qualities and relative economy. M4 is a molybdenum-tungsten high speed steel that is characterized by its high abrasion, wear resistance, transverse bend strength, and impact toughness.