valudefekt valandi pinnakihis, mis on tingitud gaaside (õhu) sattumisest sulametalli väljastpoolt (vrd suletud gaasitühik), a casting defect, on or near the surface of metal, resulting from the expansion of gas in a subsurface zone; it is characterized by a smooth bump on the surface of the casting and hole inside the casting directly below the bump (compare: blowhole)