There are several simple checks that can be made prior to sending the drawing off to suppliers to try and avoid any potential rework.

Check Your Tolerances

General tolerances like ±0.5 mm are generally acceptable for most features but close fits require tighter tolerancing. Remove superfluous tight tolerancing from other features as it can add cost without benefit.

Include Bend Allowances

Ensure that the dimensions drawn for the flat pattern of bends take into account the material bend allowance. If you are providing finished dimensions for the part, check with your supplier if they expect you to provide the flat pattern dimensions (i.e. the dimensions of the material before bending) for them to derive the finished dimensions or if they will calculate them for you.

Call Out the Material Clearly

Sheet Metal Fabrication drawings must contain information that clearly identifies the grade of material, the thickness and the surface finish that is required for the part(s) to be produced. For Sheet Metal Fabrication, visit https://dkmsheetmetal.co.uk.

Note Hole-to-Edge Distances

Ensure that holes close to edges or bends are sufficiently distant from the edges (approx. 1.5 x thickness of material).

Mark Surface Finish Requirements

Are surface finish requirements (e.g. painting, powder coating, bare) defined for the part(s) and noted on the drawing in a specified format?

Control Your Revision History

Make sure your drawings have a revision block on them. It’s so easy to issue an unlabelled file to a supplier, and for them to have no idea whether they are working with the latest version or not. Check with your fabricator that they understand which is the current version before they start making the part.

Checking your drawings before distribution will save time and money in the long run.