Sheet Metal Fabrication from Drawings & CAD Files

PDF drawing, CAD model or both?

Use the PDF to communicate dimensions, tolerances, notes, material, finish and revision. A CAD file can provide useful geometry for profiling or forming. Where both exist, send both and make sure they represent the same revision.

A 3D model without controlled notes can leave material, finish and tolerance assumptions unresolved. A 2D drawing without usable geometry may require more interpretation. Together they can make the manufacturing requirement clearer.

Start with the finished function

A fabricator needs to know what dimensions and interfaces actually matter. Identify mating holes, flange faces, connection points, overall envelope dimensions and cosmetic surfaces. That information helps distinguish a critical feature from a reference dimension.

Material needs to be explicit

State material type, grade and thickness. “Stainless” is not a complete grade. “Mild steel” may still need a specific standard or customer requirement. If material is free-issued, say so and identify what documentation accompanies it.

Show bends and formed geometry clearly

For folded sheet-metal parts, make sure bend angles, directions, radii or controlling dimensions are understandable. If the final outside dimension is critical, dimension the part in a way that makes that intent clear rather than relying only on an assumed flat pattern.

For cones, transitions and hoppers, include enough views or section information to define inlet, outlet, heights, offsets and orientation.

Tolerances should reflect function

Applying a very tight blanket tolerance can add difficulty without improving the finished product. Put tighter tolerances on the features that actually locate, seal, align or mate. Use an appropriate general tolerance for the rest if your design system supports one.

Weld information belongs on the drawing

• Which joints are welded
• Weld type/symbol where specified
• Continuous or intermittent requirement
• Whether sealing is required
• Whether welds remain visible
• Whether welds are dressed or blended
• Any inspection or qualification requirement

For stainless work, tie the weld requirement to the final finish. A visible TIG bead and a fully blended polished seam are different jobs.

Finish should not be buried in an email

Put controlled finish requirements on the drawing where possible. That includes stainless grain direction, polished faces, powder-coat colour, coating system or areas that must remain uncoated.

Use revision control

Revision confusion is one of the easiest ways to waste fabricated material. The drawing title block, file name and purchase information should make the current revision obvious. If a change affects a part already quoted or in manufacture, identify exactly what changed.

Assemblies need interface information

If Zeus is fabricating several parts that join together, send the assembly drawing. It helps reveal interfaces that may not be obvious from individual part drawings, such as access for welding, fastener orientation, flange alignment or how a formed transition connects to the next item.

What if you have only a sample or old part?

Send photographs and dimensions to start the discussion. Reverse-engineering or reproducing an existing item may require more information than a normal drawing-to-print job, particularly where hidden dimensions, material grade or original tolerances are unknown. Zeus can explain what is needed before manufacture.

Drawing checklist before requesting a quote

Frequently asked questions

Have a fabrication to price?

If this guide relates to a live job, send the drawing, material, thickness, quantity, finish, delivery postcode and required date. Zeus can then review the actual manufacturing requirement.