Hemming and seaming are two similar

metalworking Metalworking is the process of shaping and reshaping metals in order to create useful objects, parts, assemblies, and large scale structures. As a term, it covers a wide and diverse range of processes, skills, and tools for producing objects on e ...

processes in which a

sheet metal Sheet metal is metal formed into thin, flat pieces, usually by an industrial process. Thicknesses can vary significantly; extremely thin sheets are considered foil (metal), foil or Metal leaf, leaf, and pieces thicker than 6 mm (0.25 ...

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.. Hems are commonly used to reinforce an edge, hide burrs and rough edges, and improve appearance. Seams are commonly used in the food industry on canned goods, on

amusement park An amusement park is a park that features various attractions, such as rides and games, and events for entertainment purposes. A theme park is a type of amusement park that bases its structures and attractions around a central theme, often fea ...

cars, in

metal roof A metal roof is a roofing system featuring metal pieces or tiles exhibiting corrosion resistance, impermeability to water, and long life. It is a component of the building envelope. The metal pieces may be a covering on a structural, non-waterpro ...

ing (with a roof seamer), and in the automotive industry.

Process

The process for both hemming and seaming are the same, except that the tonnage (amount of force exerted) requirement is greater for seaming. The process starts by bending the edge to an acute angle. A flattening die is then used to flatten the hem.

Types

There are two types of hemmed edges: ''closed hems'' and ''open hems''. Closed hems are completely flush while open hems have an air pocket in the bend. The major difference is that the tonnage required for a closed hem is much greater than that for an open hem..

Process

Types

See also

References

Bibliography

Further reading