Ordinary low alloy steel is a kind of ordinary alloy steel containing a small amount of alloy elements (in most cases, the total amount of w does not exceed 3%). This kind of steel has high strength, good comprehensive properties, corrosion resistance, wear resistance, low temperature resistance, and good cutting and welding properties.
Under the condition of saving a lot of rare alloy elements (such as nickel and chromium), usually 1 t ordinary low alloy steel can be used for 1.2-1.3 t carbon steel, and its service life and scope of use are much longer than carbon steel. Ordinary low alloy steel can be smelted in open hearth furnace and converter with general smelting method, and the cost is close to that of carbon steel.

Round steel belongs to carbon structural steel for construction and machinery, while square steel belongs to carbon structural
steel for machinery. Both of them are simple section steel, and their section shapes are respectively round and square. Low carbon is mainly used for
drawing wire, forging rivets, bolts, nuts and other metal products of raw materials. Medium carbon round steel and square steel
are generally used to make mechanical structural parts.