MRMaschinenbaurechner

Material properties

Property cards for about 32 common engineering materials: yield and tensile strength per size range, plus Young's modulus, shear modulus, Poisson's ratio, density, thermal expansion and thermal conductivity, live with every input.

Calculation

Material group

S355J2 (1.0577)

Structural steel · EN 10025-2 · +AR/+N

Higher-loaded welded parts, crane construction, toughness down to −20 °C

Strength (size range ≤ 16 mm)

Re min. [N/mm²]355
Rm [N/mm²]470 - 630
A min. [%]22
0200400600800N/mm²ReRm

Physical properties

E [N/mm²]210,000
G [N/mm²]81,000
ν [-]0.3
ρ [kg/m³]7,850
α [10⁻⁶/K]12
λ [W/(m·K)]54

Strength ranges by dimension

Size rangeRe min.Rm [N/mm²]
≤ 16 mm355470 - 630
> 16 - 40 mm345470 - 630
> 40 - 63 mm335470 - 630
> 63 - 80 mm325470 - 630

Strength values are guaranteed minimum values of the standard (real heats lie above); physical values are typical datasheet values.

Calculation in your browser, inputs go to our server only when you export or save.

Formulas and fundamentals

Material cards

The strength values are guaranteed minimum values from the respective material standards and apply per size range. The engine picks the first range whose limit covers the entered thickness or diameter; above the largest range it deliberately warns instead of extrapolating. If the shear modulus is not stored, it is derived from:

G = E / (2 · (1 + ν))

Worked example

Strength lookup: For an S355J2 plate with t = 25 mm the range above 16 up to 40 mm applies, so Re min = 345 N/mm² and not the headline value of 355 N/mm². A quenched and tempered 42CrMo4 shaft with d = 50 mm falls into the range above 40 up to 100 mm: Rp0.2 min = 650 N/mm², Rm = 900 to 1100 N/mm².

Frequently asked questions

Where do the material properties come from?

The values are taken from the material standards, technical literature and manufacturer datasheets and are cross-checked against a second source. The standard and the supplier's inspection certificate remain decisive for the individual case.

Why does the yield strength decrease with thickness or diameter?

Thicker sections cool more slowly during rolling and heat treatment and end up with a coarser microstructure, so the standards guarantee lower minimum values there. S355J2, for example, drops from 355 to 345 and 335 N/mm², 42CrMo4 +QT from 900 via 750 to 650 N/mm². Entering the governing dimension in the tool selects the correct range automatically.

Are the displayed strength values typical values or minimum values?

They are guaranteed minimum values of the standards; real heats usually lie above them. Strength verifications are calculated with the minimum values. For condition-dependent materials such as copper alloys and for plastics the tool shows typical ranges with a note instead.

What is the difference between N/mm², MPa and bar?

1 N/mm² is exactly 1 MPa; both denote the same stress unit, and the values on this page are given in N/mm² throughout. 1 bar, in contrast, is only 0.1 MPa and is used for pressures. The legacy unit kp/mm² corresponds to 9.80665 N/mm². For further conversions there is the unit converter.

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