Bent Sheet Metal Tolerances

Refer to the chart for values for folder as well as various press brake tooling combinations.

Bent sheet metal tolerances.

Sharp inside bend radius in sheetmetal parts can cause material flow problems in soft material and fracturing in hard material. L bracket with a single bend that s 0 009 in. Angle tolerances are typically denoted by x xx. But for harder materials e g.

Bend relief and collars near pierced areas strengthen sheet metal parts. Crca inside bend radius equal to 0 65 times of sheet thickness is also enough. In the above example m and k has defined the tolerance. For bends between 0 and 90 degrees the formula is as follows.

The diagram shows one such mechanism. Recommended inside bend radius for sheet metal parts should be equal to material thickness. As per design requirements and manufacturing capability tolerance class is defined. General tolerance iso 2768 does not specify where to use these tolerances.

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 example of a 16 ga. Geometry of tooling imposes a minimum bend dimension. Use the minimum bend dimension values in the charts below for your minimum closeness of cutout to a bend.

Bend tolerances the tolerance specified by the engineer or designer tell the brake operator how much variation in the particular bend is allowable. Grain structure in the metal sheet is critical for avoiding cracks in sheet metal parts with lugs or tabs that are cut on. Typically this information is located in the title block of a drawing. ß bending angle for bends between 90 and 165 degrees the formula is.

And for machined components iso 27 68 fh can be used. 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 bends over 165 there is no need to calculate bend allowances as the neutral axis stays pretty much in the middle of the detail. 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.

For bent part fabrication tolerances start with 0 006 in. For sheet metal parts iso 27 68 mk is used.