Grain direction bend line should go across the grain for the best bend having said that a typical sharp 90 bend on a piece of 1 8 aluminum sheet should be a minimum 1 8 inside radius use either 3003 or 5052 ideally the bend line should go across the grain.
Bending aluminum sheet grain.
Bending sheet metal can be useful if it s used to build different shapes and different products.
If having bending lines perpendicular to the grain isn t practical try bending diagonal to the grain.
Applying this to metal bending be it plate bending press braking or any other type of metal forming consideration must be given to the grain direction before any process is carried out.
Divide 50 by the material s tensile reduction percentage as specified by your supplier.
Bending with the grain gives a different result than bending against it.
A metal s grain direction is usually only a factor when bending however.
If the steel has a tensile reduction value of 10 percent divide 50 by that value.
Also know that for the best results and fewer cracks on the outside of the bend the bend line should go across or diagonal to the material grain when and where possible.
Annealing and normalizing when a strain hardened material is exposed to elevated temperatures the strengthening that results from the plastic deformation of forming can be lost a bad situation if the metal needs that strength to support.
In addition the grain direction needs to be considered when the bend radius is less than twice the thickness depending on the material and its hardness.
Bend angles also can be less consistent.
The grain direction is established during the metal rolling process.
There s a rule of thumb to determine a steel s minimum bend radius and this generally works for aluminum too.
Depending on designation alloys go through different heat treatment procedures during production.
Bending the sheet metal longitudinally with the grain allows those grains to separate at the grain boundaries.
This is because sharper or tighter bends can be made across the grain without cracking.
When bending aluminum know that the smaller your inside bend radius the larger the chance that cracking will occur in the part.
General advice on aluminum.
This value will vary by grade.
Bending with the grain may result in cracking or.
Bending is a delicate and demanding process most of the time and common fabricating processes require a degree of formability that make your choice of proper alloy critical.
Bending with the grain also limits how tight of an inside bend radius you can achieve without cracking the outside of the bend.
As a general rule the grain line must run perpendicular to the bend to avoid the potential for cracking or fracture.
You must pay careful attention to grain or rolling direction when bending high strength metals especially when trying to achieve a small inside bend radius.
When bending high strength materials such as spring or high carbon steel you should orient the part so that it can be bent against the grain.
In high purity forms aluminum is soft and ductile.
