Here s a good rule of thumb for most materials.
How to bend aluminium sheet metal.
Let s consider a challenging job.
Cut the section of metal out or otherwise prepare the metal to be bent by removing any burrs or sharp edges.
You d probably air bend by using a 3 0 in.
In other words if you re bending 1 8 sheet use a tool with a 1 8 radius to form the inside of the bend.
Then place the clamp bar back down on top of the aluminum crosswise.
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It is important to make sure that the sheet is properly pushed onto the wipe die.
The inside bend radius should be equal to the thickness of the material that you re forming.
Now that you know your bend allowance take your protractor and draw a clear line with your marker across the point at which you will bend your sheet metal.
Make sure the bar is seated firmly inside the frame.
Determine the angle at which you want to brake the metal and mark it on the protractor.
The slack between the wipe die and the punch plays an important role in getting a good result.
Insert your aluminum sheet into the brake beneath the removable clamp bar.
Say you re bending 0 25 in thick 6061 t6 aluminum to a 100 degree external angle 80 degree internal angle.
Lift the clamp bar away from the rear of the brake frame and slide the sheet in perpendicularly to the direction you want to bend it.
Wipe bending or edge bending is another way to bend sheet metal edges.
Mark your bend lines.
You will use the protractor to gauge the brake as you bend the metal little by little.
Simple sheet metal bender using a hand roller clamps and plywood.
Then use your bend allowance to draw your second bend line the intervening distance between your bend lines bend radius.
As a result the wipe die also determines the bend s inner radius.