bead

A small convex molding usually having a continuous cylindrical surface. Photo from Mackinac Island, Michigan, 2019. 2. An edge of sheet metal stiffened by bending and flattening a narrow strip or rolling the edge into a tube shape. 3. A continuous deposit of fused metal. Also called weld bead. 4. A narrow deposit of sealant applied to a building joint. (Ching, 1995)
bead molding, astragal, half round, stop-bead, beads, weld bead