Bent Sheet Metal Tolerances

The sheet metal bending height should be at least 2 times the thickness of the sheet metal plus the bending radius that is h 2t r.

Bent sheet metal tolerances.

Geometry of tooling imposes a minimum bend dimension. L bracket with a single bend that s 0 009 in. General tolerance iso 2768 does not specify where to use these tolerances. As per design requirements and manufacturing capability tolerance class is defined.

ß bending angle for bends between 90 and 165 degrees the formula is. Angle tolerances are typically denoted by x xx. Recommended inside bend radius for sheet metal parts should be equal to material thickness. Typically this information is located in the title block of a drawing.

But for harder materials e g. For bends between 0 and 90 degrees the formula is as follows. The diagram shows one such mechanism. Both benson and boden emphasized that a precision bending operation can achieve some very tight tolerances but it takes time money and effort to achieve them.

For bent part fabrication tolerances start with 0 006 in. As benson explained these would be the possible errors over the three flange dimensions and four bends involved in attaining the 6 110 in. 1 all manufacturing tolerances used up to that point such as laser cutting tolerances welding tolerances and more 2 all bend tolerances for the entire part added together we call this an uncontrolled dimensions because there are additional tolerances to consider. And for machined components iso 27 68 fh can be used.

Sharp inside bend radius in sheetmetal parts can cause material flow problems in soft material and fracturing in hard material. Crca inside bend radius equal to 0 65 times of sheet thickness is also enough. Uncontrolled dimensions contain two different categories of tolerances. Bend relief and collars near pierced areas strengthen sheet metal parts.

To allow for accuracy of the fabrication equipment and add 5 percent of the thickness for each bend. In the above example m and k has defined the tolerance. For sheet metal parts iso 27 68 mk is used. In the example of a 16 ga.

Grain structure in the metal sheet is critical for avoiding cracks in sheet metal parts with lugs or tabs that are cut on. Use the minimum bend dimension values in the charts below for your minimum closeness of cutout to a bend.