A rectangular parallelepiped ingot defined by a height H, a width W and a length L, having longitudinal faces extending between two end faces, having a volume between 0.15 m.sup.3 and 0.80 m.sup.3 and a surface area to volume ratio between 10 m.sup.?1 and 18 m.sup.?1, made of at least one metal, including at least one notch and a notch tip along the ingot length, wherein the at least one notch is configured such that: MaxD<H/2, MaxD<W/2 and MaxD being the maximum distance between any point of the ingot and the closest surface of the ingot.