From Surf Wiki (app.surf) — the open knowledge base

Hemming and seaming

Metalworking Process

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.

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 cars, in metal roofing (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.

Material thickness [mm]	Open hem	Closed hem
0.6	9	23
0.8	12	32
1.0	15	40
1.2	17	50
1.6	24	63
2.0	30	80
2.6	55	90
3.2	70	100
4.5	105	200

References

Bibliography

References

{{harvnb. Benson. 1997
{{harvnb. Benson. 1997

Info: Wikipedia Source

This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page.

metal-forming

Want to explore this topic further?

Ask Mako anything about Hemming and seaming — get instant answers, deeper analysis, and related topics.

Research with Mako

Free with your Surf account

Content sourced from Wikipedia, available under CC BY-SA 4.0.

This content may have been generated or modified by AI. CloudSurf Software LLC is not responsible for the accuracy, completeness, or reliability of AI-generated content. Always verify important information from primary sources.

Report

Material thickness [mm]	Open hem	Closed hem
0.6	9	23
0.8	12	32
1.0	15	40
1.2	17	50
1.6	24	63
2.0	30	80
2.6	55	90
3.2	70	100
4.5	105	200

Material thickness [mm]	Open hem	Closed hem
0.6	9	23
0.8	12	32
1.0	15	40
1.2	17	50
1.6	24	63
2.0	30	80
2.6	55	90
3.2	70	100
4.5	105	200

Material thickness [mm]	Open hem	Closed hem
0.6	9	23
0.8	12	32
1.0	15	40
1.2	17	50
1.6	24	63
2.0	30	80
2.6	55	90
3.2	70	100
4.5	105	200