What is HSS?

High-speed steel (HSS) has been the standard for metal cutting tools since the 1830s.

High-speed steel (HSS) is a tool steel with high hardness, high wear resistance, and high heat resistance. It is also called sharpened steel, which means that it can harden and remain sharp even when cooled in the air during quenching.

High-speed steel contains a high percentage of carbon and other metals. Considering that composition is the most important characteristic of high-speed steel, HSS contains tungsten, molybdenum, chromium, vanadium, cobalt, and other carbide-forming elements in a total amount of about 10 to 25% of alloying elements. These compositions provide HSS with classic cutting and mechanical properties such as wear resistance. In the quenched state, iron, chromium, s    ome tungsten, and a large amount of carbon in high-speed steel form extremely hard carbides that can improve the steel's wear resistance.

In addition, HSS is known to have high hot hardness. This is because tungsten is dissolved in the matrix. The hot hardness of high-speed steel can reach 650 degrees. Tungsten, molybdenum, chromium, vanadium, cobalt, and other carbides contain elements that help maintain high hardness at high-temperature cutting (about 500°C).

Comparing HSS to carbon tool steels can know which have a higher hardness at room temperature after being quenched and tempered at low temperatures. But when the temperature is higher than 200°C, the hardness of carbon tool steel will drop sharply. Furthermore, the hardness of carbon tool steels at 500°C will drop to a similar level to that of its annealed state, which means that its ability to cut metal is completely lost. This phenomenon limits the use of carbon tool steels in cutting tools. High-speed steels make up for the key shortcomings of carbon tool steels due to their good hot hardness.

Cemented carbide is superior to HSS in most cases. If you are interested in tungsten carbide products and want more information and details, you can CONTACT US by phone or mail at the left or SEND US MAIL at the bottom of the page. We're looking forward to your inquiry.