Sheet metal is wonderfully fast to manufacture when the design respects the process.
It becomes frustrating when the CAD model ignores how the sheet actually bends, stretches and gets assembled.
Here are five mistakes worth checking before you release a sheet-metal drawing.
## 1. Holes too close to bends
A hole near a bend can distort during forming.
The exact safe distance depends on material, thickness, tooling and process, so avoid relying on one universal number.
Check the fabricator’s process capability.
## 2. No bend relief
When two bends meet near a corner, material can tear, deform or create an unwanted bulge.
A properly designed bend relief gives the material somewhere to move.
The relief should match the manufacturing process and required appearance.
## 3. Unrealistic bend radii
A very small inside radius may look harmless in CAD.
The press brake does not care what the CAD model says.
Material thickness, alloy, tooling and grain direction all affect bending behaviour.
Use realistic tooling information when defining the bend.
## 4. Overly tight tolerances
Sheet metal is a formed process.
If every dimension is given an extremely tight tolerance, production becomes expensive and inspection becomes difficult.
Identify functional dimensions and control those more carefully.
## 5. Forgetting assembly sequence
This one causes surprisingly many problems.
A bracket may be perfectly bendable but impossible to assemble because one flange blocks access to the fastener.
Before release, mentally assemble the part.
Ask:
“Can a person actually put this together?”
## A better sheet-metal workflow
Start with the manufacturing process.
Then create the base feature, define bends, add reliefs, place holes and check the flat pattern.
Finally, inspect the finished formed condition—not only the unfolded model.
## Shop-floor thinking matters
If you have access to a fabrication shop, spend time there.
Watch one part being cut.
Watch it being bent.
Look at where operators struggle.
Those observations will improve your CAD work more than another hour of random modelling practice.
Good sheet-metal design is learned partly from software and heavily from reality.
2026 Engineering Update
Mechanical engineering is moving toward more connected design-to-manufacturing workflows. Three developments are especially useful for engineers:
- AI-assisted engineering: AI is increasingly being used alongside CAD, simulation and engineering data to explore designs and reduce repetitive work.
- Digital twins and digital threads: connected product and manufacturing data can help teams validate changes earlier and maintain better traceability from design through production.
- Design-for-manufacturing skills: engineers are increasingly expected to combine 3D CAD, simulation, GD&T, DFM/DFA, automation and data skills rather than work in isolated disciplines.
The practical takeaway: learn the fundamentals first, then use new digital tools to make engineering decisions faster, clearer and easier to validate.