Bent Sheet Metal Tolerances

Typically this information is located in the title block of a drawing.

Bent sheet metal tolerances. For bends over 165 there is no need to calculate bend allowances as the neutral axis stays pretty much in the middle of the detail. L bracket with a single bend that s 0 009 in. Recommended inside bend radius for sheet metal parts should be equal to material thickness. Use the minimum bend dimension values in the charts below for your minimum closeness of cutout to a bend.

Refer to the chart for values for folder as well as various press brake tooling combinations. For bent part fabrication tolerances start with 0 006 in. To allow for accuracy of the fabrication equipment and add 5 percent of the thickness for each bend. 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.

In the above example m and k has defined the tolerance. As per design requirements and manufacturing capability tolerance class is defined. Uncontrolled dimensions contain two different categories of tolerances. As benson explained these would be the possible errors over the three flange dimensions and four bends involved in attaining the 6 110 in.

Crca inside bend radius equal to 0 65 times of sheet thickness is also enough. And for machined components iso 27 68 fh can be used. Angle tolerances are typically denoted by x xx. Geometry of tooling imposes a minimum bend dimension.

Grain structure in the metal sheet is critical for avoiding cracks in sheet metal parts with lugs or tabs that are cut on. 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 sheet metal parts iso 27 68 mk is used. In the example of a 16 ga.

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. Sharp inside bend radius in sheetmetal parts can cause material flow problems in soft material and fracturing in hard material. Bend relief and collars near pierced areas strengthen sheet metal parts. But for harder materials e g.

The diagram shows one such mechanism. ß bending angle for bends between 90 and 165 degrees the formula is.