Aviation Dictionary
اتصال لب به لب ، اتصالی که دو لبه قطعات در کنار به یکدیگر جوش داده شده باشند
A type of welded joint in which the pieces of metal to be joined are placed so their edges touch, but do not overlap. the edges of both pieces of metal are melted, and filler rod is added to form a bead between the two pieces.