Upper Yield Point (σsu): The maximum stress reached before the force first decreases upon yielding of the sample; Lower Yield Point (σsl): The minimum stress during the yielding stage, when the initial instantaneous effect is not considered.

The yield point calculation formula is:

In the formula: Fs--Yielding force (constant) during the tensile process of the sample, N (Newton); So--Original cross-sectional area of the sample, mm².

3. Elongation at Break (σ)

In tensile testing, the percentage increase in length of the gauge section after the specimen breaks is known as the elongation. It is represented by σ and is measured in percent. The calculation formula is: σ = (Lh - Lo) / L0 *

In summary, based on various usage requirements, seamless square tubes specify tensile properties (tensile strength, yield strength or yield point, elongation) as well as hardness and toughness indicators. For more information, please keep an eye on our website. We have professional customer service staff at your service. Thank you for your support.