Tolerance class is defined as per design requirements and manufacturing capability.
Sheet metal tolerances table.
The resulting bend angle variation and sometimes the required adjustment to the flat layout contributes to the reason that machined parts typical tolerance of 0 002 in can routinely have tighter tolerances than precision sheet metal parts typical tolerance of 0 010 in.
The tolerances in the table and attachments reflect current manufacturing practices and commercial standards and are not representative of the manufacturer s standard gauge which has no inherent tolerances.
Sheet metal thickness inch metric suggested sheet metal tolerances hole to hole edge to hole edge to edge fold to hole 024 0 60 fold to fold hole size 003 0 08 0 003 0 000 0 08 0 0 080 2mm 080 2mm fold to edge flange length 1 fold angle angularity feature hardware hole assy item to fold assy item to edge assy item to assy item.
And for machined components iso 2768 fh can be used.
General tolerances for linear and angular dimensions din iso 2768 t1 linear dimensions.
Uncontrolled dimensions contain two different categories of tolerances.
For sheet metal parts iso 2768 mk is used.
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.
Variations on dimensions without tolerance values are according to din iso 2768 mk.
1989 general tolerances part 2.
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.
Sheet metal guage tolerances during the rolling process the rollers bow slightly which results in the sheets being thinner on the edges.
For example 18 gauge steel according to a gauge conversion chart is 0 0478 inch or 1 214 millimeter.
General tolerances to din iso 2768.