Copper has good toughness, can remain stable under high pressure conditions, and has natural lubrication function. However, due to the scarcity of copper resources and the high price of copper , the amount of copper used in the military industry is very large, and China has to look for alternative materials. Steel is cheap, and China is a major steel producer in the world. However, directly using steel to make bullets will face some problems, such as the lack of sufficient lubricity of steel, which may cause the gun chamber to be blocked and is not suitable for combat.

a process of producing composite materials by hot rolling of two or more metal materials . The metal substrate and the surface material are stacked together and rolled at high temperature and high pressure.

The three-layer copper-stainless steel composite plate is a layered composite of high-performance non-ferrous copper and high-strength stainless steel through a cold rolling process. The material has good corrosion resistance, high bonding strength, comprehensive mechanical properties, and the thermal conductivity and decorative properties of copper.

A new type of composite plate that is cold-rolled and composited with high-performance, high-purity copper and other high-performance carbon steel plates. While retaining the good performance of the original material, it can reduce the material cost by replacing "expensive" with "cheap"; or replace "plating" with "composite" to produce corrosion-resistant cladding products without pollution and improve the corrosion resistance of the coating.

Stainless steel aluminum multilayer composite plate is mainly used for cookware blanks and thermal and magnetic conductive sheets. It is a new energy-saving and environmentally friendly double-layer/multi-layer metal material with 1050 pure aluminum/3003 aluminum alloy as the matrix, single-sided or double-sided cold rolling composite process, and continuous coating of a certain thickness of 304/316/430 and other stainless steel.

Stainless steel aluminum multilayer composite plate is mainly used for cookware blanks and thermal and magnetic conductive sheets. It is a new energy-saving and environmentally friendly double-layer/multi-layer metal material with 1050 pure aluminum/3003 aluminum alloy as the matrix, single-sided or double-sided cold rolling composite process, and continuous coating of a certain thickness of 304/316/430 and other stainless steel.

Rebar refers to steel used for reinforced concrete and prestressed reinforced concrete. Its cross section is round, or sometimes square with rounded corners. It includes plain round steel bars, ribbed steel bars, and twisted steel bars.

Round steel refers to a solid long steel bar with a circular cross section. Its specifications are expressed in diameter, in millimeters (mm).

Steel sheet piles are a type of steel structure with linkage devices on the edges that can be freely combined to form a continuous and tight retaining wall or water retaining wall.

‌Square steel is a steel with a square cross section, and its cross section is square or rectangular. ‌Square steel is processed into various shapes and sizes by pressure, and is named because of its square cross section.