Hemming and Seaming

Hemming and seaming are two similar metalworking processes in which a sheet metal edge is rolled over onto itself. Hemming is the process in which the edge is rolled flush to itself, while a seam joins the edges of two materials.

1. Hemming

Straight Hem.
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Contour hemming.
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Hem detail.
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Types of Hemming.
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Hemmed component example.
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Hemming on an automobile part.

The accuracy of the hemming operation is particularly important since it affects the appearance of the surface and surface quality. Improperly done hemming causes dimensional variations and material deformations such as wrinkles in the flange.

Hemming ensures better edge stiffness to a sheet. Hemming also helps in creating a smooth surface to touch instead of a sharp edge typical of sheets.

2. Seaming

Hand Seamer.
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Desktop Seamer.

Seamed Roofing Sheets
Seaming is when two partly hemmed edges are joined together to form a seal. Seams are commonly used in the food industry on canned goods. Seams are also used to seam two roofing sheets together in the building industry.

Types of Seams.
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Seaming forms a hermitical seal between the body and cover of a can.
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