Types of metal

STAK Ltd. produces castings from the following types of steel:

Depending on the quantitative content of alloying additives, when they are more than 10%, the steel is classified as high-alloy.
The type and the amount of additives are carefully selected to achieve certain properties. For example, increasing the Mn content increases the wear resistance, improves the mechanical properties of the steel, combining high ductility and strength.

From high-alloy manganese steel are produced: units for chains of tractors and other chain machines, linings for ball mills, crushing and lining plates for jaw crushers, hammers and lining plates for rotary crushers, cones and pressure bushings for cone crushers used in mining, coal mining and cement industries.

Highly wear-resistant parts are also produced: teeth for excavators, fadroms, front loaders, knives for bulldozers and graders, working on impact load with abrasive wear, blades, holders and linings for asphalt mixers and concrete mixers, as well as other spare parts on customer’s request.

Steels with an alloying content of less than 10% are called low-alloy steels. The type and quantities of impurities are carefully selected to achieve certain properties such as: hardness, corrosion resistance and reducing the fragility of parts that are made of steel.


От нелегирани и нисколегирани стомани се произвеждат резервни части за трактори и селскостопански машини, плугове, плужни тела и лемежи за плугове, опорни ролки, сечива , ходови колела, лагерни тела, сечива и др.

Gray cast irons have excellent wear-resistant characteristics. Due to the structure of the material and the addition of various alloying elements, the mechanical properties of cast iron are improved. Compared to low- and medium-carbon steel, gray cast iron has higher strength as well as excellent resistance to deformation.

Cast iron is used to make: weights, plates, caps, cones, drums, brackets, flywheels, pulleys, bearing bodies, street grilles and shafts, etc.

The group of modified cast irons includes the so-called ductile iron/ Spherographite cast , which is characterized by a high degree of elasticity. Like gray cast iron, there are many types of ductile iron with varying degrees of strength and ductility. The different types are achieved through a combination of aluminum additives and heat treatment.

Spherographite cast/ductile iron is very easy to machinинг and allows the requirements for machining to be met to maximum accuracy.

COMPARATIVE TABLE OF METALS (Standards & Grades)