Minimum sheet metal flange bend length 3 x sheet thickness bend radius.
Dimensioning sheet metal bends.
Bends on the same plane should occur in the same direction.
Sheet metal parts with a minimum of 0 9mm to 20mm in thickness can be manufactured.
Refer to the chart for values for folder as well as various press brake tooling combinations.
Bend length 0 010 0 25mm.
A 1 degree tolerance on all bend angles.
As one who daily works with sheet metal design and fabrication use outside flange lengths for several reasons.
Folder bend length 0 010 0 25mm per bend for controlled dimension.
D 2 5t r see below the height can be less but it required secondary operations and is far more costly.
Bends specified as angles may be toleranced at plus or minus one half.
The best way to measure a hem from the outside radius to the hem edge is with a surface plate angle block and a height gauge.
Use the minimum bend dimension values in the charts below for your minimum closeness of cutout to a bend.
These dimensions may seem helpful but after your manufacturer makes bend deductions based on their capabilities and other bending factors your dimensions will become unusable.
Geometry of tooling imposes a minimum bend dimension.
Upon close examination of the bends we find that the sheet metal stretches on the outer surface and that the inside surface seems to shrink.
In low carbon steel sheet metal the minimum radius of a bend should be one half the material thickness or 0 80 mm 0 03 inch whichever is larger.
It shall be equal to three times of sheet thickness plus bend radius.
When designing parts for laser cutting one should not make holes smaller than the thickness of the material.
Form height to thickness ratio to determine the minimum form height for sheet metal use the following formula.
No worries of forgetting a material thickness along the way 3.
When you figure flat pattern length you simple add up all the outside flanges and subtract the bend deductions.
Avoid large sheet metal parts with small bent flanges.
Bends in sheet metal are manufactured using sheet metal brakes.
Sheet metal stretches when it bends is an oversimplification.
Press brake bend length 0 010 0 25mm per bend for controlled dimension.
Minimum sheet metal flange bend length is required to avoid cracks in the bending area.
Bend angle 1 degree.
Figure 3 because the bend line shifts after forming the edge to inside surface dimension will be greater than the edge to bend line dimension.
5 edge distortion an exaggerated example of edge deformation is pictured in figure a below.
