How To Note Flatness Sheet Metal Drawings

A bend table lists propertied of all bends in a flat pattern view of a sheet metal part.

How to note flatness sheet metal drawings.

Minimum bend reliefs allowed. To control the bow try using straightness applied to your sheet metal gauge thickness feature of size. It comes in useful if a feature is to be defined on a drawing that needs to be uniformly flat without tightening any other dimensions on the drawing. It is a common symbol that references how flat a surface is regardless of any other datums or features.

The left figure shows the drawing callout. No mmc or lmc applicable. The boxed symbols can be read this surface must lie between two parallel planes spaced 0 2 apart in all views the right figure shows a possible actual part condition. Bend tags are formatted by the dimension style and do not have a leader by default.

I want stress relief radii. Gd t flatness is very straight forward. I systematrically specify bend radii on my drawings and i include details showing what the bend corners look like before bending. Toggling the visibility of sheet metal bend notes.

I am apply my dimensions carefully so that they are unambiguous. To put a flatness on sheet metal part will be hard to control because of the stock sheet metal gauge size tolerances are relatively nice and tight. Flat pattern drawing views can display bend line notes or bend tables. After you insert the bend table in the drawing bend tags are added to the selected drawing view automatically.

Unless you need the part to have a flatness that is better than the sheet metal gauge tolerance. Dimensions given on a flat pattern are affected by several bending factors like k factor and bend radius during the 3d modeling stage. Perfect flatness is when all points of a surface lie in the same plane. Yes new in 2009 drawing callout.

Bending factors affect the flat pattern. Toggling the visibility of bend lines. Toggling the visibility of bend region lines. I don t put any standard notes on my sheet metal drawings.

Although notes on each drawing will differ the first note on all sheet metal drawings that contain bends should be as follows. The flatness control c defines how much a surface on a real part may vary from the ideal flat plane. I have read up on and taken a course on the asme y14 5m 1994. Sheet metal bend line notes.

Creating drawings of flat patterns. Flatness is a form control. Note that the flatness tolerance must be less than the size tolerance associated with the surface. The flatness control c defines how much a part s surface may deviate from its perfect flat form.