Yield Strength: The minimum yield strength of P355NH is 355 MPa, which is the amount of stress required to permanently deform or cause failure in the material.

The mechanic properties of P355NH and P355GH are:

1. Tensile Strength: The tensile strength of P355NH is between 490-630 MPa, while for P355GH it is between 510-650 MPa. Tensile strength is the maximum amount of stress a material can withstand before breaking or failing under tension.

2. Yield Strength: The yield strength of P355NH is minimum 355 MPa, while for P355GH it is minimum 355 MPa. Yield strength is the amount of stress a material can withstand before it starts to deform permanently.

3. Elongation: The minimum elongation of P355NH is 22% (longitudinal) and 17% (transverse), while for P355GH it is 22% (longitudinal) and 17% (transverse). Elongation is the percentage increase in length of a material before it breaks under tension.

4. Impact Strength: The impact strength of P355NH is minimum 27 Joules at -20°C, while for P355GH it is minimum 27 Joules at 0°C. Impact strength refers to the ability of a material to absorb energy under sudden impact loads.

5. Hardness: The maximum hardness of P355NH is 160 HB, while for P355GH it is 120-160 HB. Hardness is the measure of a material’s resistance to penetration or indentation.

These properties are important in determining the suitability of P355NH and P355GH for various mechanical applications, such as pressure vessels, boilers, and piping systems in the oil and gas industry.