Dimensioning Sheet Metal Bends

Use the minimum bend dimension values in the charts below for your minimum closeness of cutout to a bend.

Dimensioning sheet metal bends. D 2 5t r see below the height can be less but it required secondary operations and is far more costly. 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. 5 edge distortion an exaggerated example of edge deformation is pictured in figure a below.

Form height to thickness ratio to determine the minimum form height for sheet metal use the following formula. Minimum sheet metal flange bend length is required to avoid cracks in the bending area. When designing parts for laser cutting one should not make holes smaller than the thickness of the material. Geometry of tooling imposes a minimum bend dimension.

A 1 degree tolerance on all bend angles. This is a common occurrence when manufacturers receive a sheet metal layout dimensioned in the flat pattern. The diagram shows one such mechanism. 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.

Bends in sheet metal are manufactured using sheet metal brakes. Bend length 0 010 0 25mm. Minimum sheet metal flange bend length 3 x sheet thickness bend radius. The basics of applying bend functions the fabricator november 2012 by steve benson explains it in detail.

Sheet metal stretches when it bends is an oversimplification. Press brake bend length 0 010 0 25mm per bend for controlled dimension. Bend angle 1 degree. When you figure flat pattern length you simple add up all the outside flanges and subtract the bend deductions.

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. As one who daily works with sheet metal design and fabrication use outside flange lengths for several reasons. 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. Folder bend length 0 010 0 25mm per bend for controlled dimension.

Bends on the same plane should occur in the same direction. Bends specified as angles may be toleranced at plus or minus one half. No worries of forgetting a material thickness along the way 3. Sheet metal parts with a minimum of 0 9mm to 20mm in thickness can be manufactured.