the mechanical properties of the materials used, reflecting, where appropriate, matters such as strength, ductility, fracture resistance, wear resistance and fatigue resistance;
airíonna meicniúla na n-ábhar a roghnaítear, lena léirítear, más iomchuí, cúrsaí amhail neart, insínteacht, seasmhacht in aghaidh briste, seasmhacht in aghaidh caithimh agus seasmhacht in aghaidh tuirse;