As living standards rise, so does the diversity of needs, giving rise to seamless square tubes. Now, seamless square tubes are an indispensable item in daily life, as well as in industrial construction and other fields. The mechanical properties of steel are a crucial indicator for ensuring the ultimate performance (mechanical properties) of steel, which depend on the chemical composition of the steel and the heat treatment process.

1. Tensile Strength (σb)

The stress (σ) that the sample withstands at the point of breaking during the tensile process, calculated by dividing the maximum tensile force (Fb) by the original cross-sectional area (So) of the sample, is known as the ultimate tensile strength (σb), with units of N/mm² (MPa). It represents the maximum ability of the metal material to resist breaking under tensile force.

2. Yield Point (σs)

Materials with yielding phenomenon, the stress at which the specimen continues to elongate without an increase in force (remaining constant) during the tensile process is called the yield point. If the force decreases, the upper and lower yield points should be distinguished. The unit of the yield point is N/mm² (MPa).