Hems are commonly used to reinforce an edge hide burrs and rough edges and improve appearance.
Aluminum sheet metal hem.
When working with a brake press hems are always created in a two step process.
Material bend radii and minimum bend size charts.
Minimum acute flat for aluminum mt x 2 minimum acute punch radius for aluminum minimum flat length x 2 hemming and seaming hemming and seaming are basically the same process.
With plated steel parts the interior of the hem can be very difficult to cover for corrosion control.
The gauge of course refers to the thickness of sheet metal.
In sheet metal hemming means to fold the metal back on itself.
Hems have drawbacks however.
The hem is primarily used for reinforcement safety and edge appearance figure 4.
Abn sheet metal hand seamer 3 inch straight jaw manual metal bender tool sheet metal bending pliers flattening tool 4 5 out of 5 stars 144 27 89 27.
Sheet metal hemming process finds its major applications in the manufacturing of parts pertaining to the automotive parts.
In car part production hemming is used in assembly as a secondary operation after deep drawing trimming and flanging operations to join two sheet metal parts outer and inner together.
Create a bend with acute angle tooling in the metal 30 is preferable but 45 will work for some circumstances.
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 can be useful as a way to stiffen a sheet metal panel.
Automotives parts such as deck lids trunk lids doors hoods and tailgates formed by hemming process requires sheet material to have high strength to weight ratio with excellent bending abilities without crack and fracture.
High gauge sheet metal is thicker than low gauge sheet metal which can make it difficult to manipulate using processes like hemming.
And while hems or seams reinforce a sheet metal edge their main purpose is to improve appearance by hiding burrs and rough edges on metal back splashes and other sheet metal installations.
Typical parts for this type of assembly are hoods doors trunk lids and fenders.
With the right tools however manufacturing companies can hem sheet metal by bending and rolling the edge over and onto itself.
The bend radius you select may not be available if the geometry of the part will not allow us to bend with the specific tooling required to achieve that radius.