6. Choosing structural steel

Choice of shade

The grade characterizes strength performance. Depending on the section design conditions, the best value for money is achieved by selecting the section with the lowest CP cost (with C cost per kilogram and P linear mass, in kilograms). Higher-performance grades have a higher cost per kilogram, but require a lower weight per metre. High-strength grades (e.g. S420) are often more advantageous as long as only the strength condition is met, i.e. the stress must not exceed the yield point, as the cost per kilogram increases less rapidly than the yield point.

Within the scope of a product's supply possibilities, the choice of steel grade is essentially made on the basis of the work rate (not forgetting possible fatigue stresses) which, affected by the safety coefficient, determines the level to be reached...