Supply chain issues have been an increasing problem for our clients recently, and lead times for mechanical and electrical parts are significantly longer than usual.  This also applies to structural steel, where the higher sub-grades are particularly difficult to find at present.  Higher sub-grades are often specified where thick plates must be used in order to satisfy fracture toughness requirements from the design codes, but the normal methods applied for sub-grade selection can be extremely conservative in some circumstances.

One of our clients are currently manufacturing a steel footbridge and found themselves in such a situation.  The bridge included a fabricated beam made from thick plates (~120mm flanges), for which the designer had specified S355 ML/NL steel: the highest sub-grade available.  They were unable to source this material within a sensible timescale to allow the manufacture to progress on time.

Eadon Consulting were able to assist by carrying out a more detailed assessment of the fracture toughness requirements for the part, and provide them with confidence that S355 J2, a significantly lower sub-grade, could be safely used for this application.  This assessment was turned around rapidly, allowing fast procurement of the new material and avoiding a lengthy delay.