Tungsten carbide (hard alloy) possesses a series of excellent properties such as high hardness, wear resistance, good strength and toughness, heat resistance, and corrosion resistance. In particular, its high hardness and wear resistance remain largely unchanged even at temperatures of 500°C, and it still maintains high hardness at 1000°C.

Tungsten steel, also known as hard alloy, refers to a sintered composite material composed of at least one metal carbide. Tungsten carbide, cobalt carbide, niobium carbide, titanium carbide, and tantalum carbide are common components of tungsten steel. The grain size of the carbide component (or phase) typically ranges between 0.2-10 micrometers, and the carbide grains are bonded together using a metal binder. The binder is usually metallic cobalt (Co), but for specific applications, nickel (Ni), iron (Fe), or other metals and alloys can also be used. A specific combination of carbide and binder phase composition is referred to as a "grade."

The classification of tungsten steel is based on ISO standards. This classification is determined by the type of workpiece material (such as P, M, K, N, S, H grades). The binder phase composition is primarily utilized for its strength and corrosion resistance.

The matrix of tungsten steel consists of two parts: one is the hardening phase, and the other is the binder metal. The binder metal is typically a ferrous metal, commonly cobalt or nickel. Hence, there are tungsten-cobalt alloys, tungsten-nickel alloys, and tungsten-titanium-cobalt alloys.

Tungsten-containing steels, such as high-speed steel and certain hot-work tool steels, significantly enhance the hardness and heat resistance of the steel due to the tungsten content, but the toughness drastically decreases.

The primary application of tungsten resources is also in hard alloys, i.e., tungsten steel. Hard alloys, known as the teeth of modern industry, are widely used in various tungsten steel products.