Seam

A seam is the line where two pieces of material join or meet. The term is used across textiles, engineering, and geology to describe the boundary formed by joining surfaces. Seams may be visible or concealed depending on technique and purpose.

In sewing, a seam is created by stitching fabric edges together to form a garment or item. Common types include plain seams, French seams, and flat-felled seams, with finishes such as overlocking or serging. Seam allowances typically range from roughly 1/4 to 5/8 inch (6–15 mm) depending on fabric and purpose.

In geology and mining, a seam refers to a continuous bed of mineral deposit, most notably a coal seam. Seams vary in thickness and mineral quality and are targeted by specific extraction methods, such as room-and-pillar or longwall mining. The economics and safety of mining are closely tied to seam characteristics.

In metalworking and manufacturing, a seam is the joint line formed by joining sheet components, often by welding, riveting, or clinching. Seams can be sealed for pressure containment in cans and tanks or left as exposed joints in structural assemblies.