Alloy 65G is a quality structural steel with high carbon content and a total amount of alloying additions not exceeding 2.5%. It belongs to the family of spring steels. It is used to manufacture a wide variety of products: from critical units of industrial equipment to cold weapons. Physical-chemical characteristics are determined by GOST 14959-2016.
The 65G marking includes information on the steel’s composition, type, and main properties. The designation begins with a numeric code indicating the amount of carbon in the alloy composition. The digits imply hundredths of a percent: according to GOST, carbon content in the steel is at least 0.65% but not more than 0.7%.
The symbol “G” in the marking of spring steels indicates elevated (relative to the standard value) manganese content. For alloy 65G the range of this alloying element is from 0.9% to 1.2%. Adding the heavy metal in such proportions makes it possible to raise important characteristics of the structural alloy such as hardness, toughness, and elastic modulus, and also to improve its hardenability.
Besides manganese, other alloying elements are also added when melting steel 65G. They are not indicated in the marking but are necessary for the alloy to acquire the desired properties. The precise chemical composition of 65G is regulated by GOST and includes approximately 97% iron (Fe). The alloying elements are:
Alloy 65G is characterized by high strength, hardness, and wear resistance, which makes it suitable for use in various industrial areas. The required properties are achieved thanks to a certain steel melting technology. Heat treatment of 65G includes annealing, quenching, and tempering.
Steel 65G can be processed by ordinary methods, but due to high hardness and strength it requires low speeds and large forces in cutting. Grinding and polishing are also possible, but diamond tools are recommended. Welding this alloy is quite difficult: it provides for preheating and post-weld heat treatment to avoid formation of cracks and deformation.
High hardness, wear resistance, and toughness of steel 65G make it suitable for use in areas where high strength and durability of installed parts are needed. Various springs and leaf springs for construction equipment, automotive and railway transport, gears for industrial equipment units, collets, flanges, and much more are made from it.
One of the most interesting application areas of 65G is manufacturing bladed weapons, in particular throwing knives and swords for sports competitions and reconstructions of various historical periods. For kitchen and hunting knives such an alloy is unfortunately unsuitable, as it oxidizes on contact with water. Exactly because of susceptibility to corrosion, when using parts from steel 65G, especially in aggressive environments, it is extremely important to provide them with proper care and maintenance.
In addition, although steel 65G has high strength, it is unsuitable for elements and structures subject to impact loads, as this may lead to cracking and destruction of the metal. In such cases other steel types may be more suitable, for example low-carbon or medium-carbon.
In conclusion it should be noted that steel 65G is a universal and widely used material in various industries thanks to its high strength, hardness, and wear resistance. However, when choosing an alloy for a specific application one should take into account its susceptibility to rust and limited suitability for impact loads.
Petersburg Plant of Precision Alloys supplies high-carbon steel 65G as cold-rolled strip produced to GOST 21996-76 “Cold-rolled heat-treated steel strip.” The blanks released are suitable for creating products of more complex shapes, including various springs and leaf springs. Contact us and we will help select a steel grade matching your tasks.
