Sheet Metal Fabrication: Bending, Stamping & Surface Treatment
AI Summary: Sheet metal fabrication includes laser cutting, punching, bending, welding, grinding and surface treatment. Design should consider minimum bend radius, bend deduction, process holes, edge margins and assembly clearance. Surface options include spray painting, powder coating, anodizing or zinc plating; drawings must specify grain direction, color difference and protection requirements.
Procurement Checklist
| Review Item | Selection Points |
|---|---|
| Unfolding Process | Reasonable bend radius and deduction |
| Hole edge margin | Hole distance to bend edge must not be too close |
| Tolerance fit | Assembly verification with other parts |
| Welding and grinding | No weld burn-through, no obvious grinding marks |
| Surface coating | Film thickness, color difference and adhesion |
Procurement, Installation and Usage Points
1. Avoid cracking in bent parts
Material and radius must match.
2. Pre-treatment before spraying
Degreasing and rust removal affect coating life.
3. Enclosure grounding and EMI
Electrical sheet metal requires consideration of conductivity and grounding.
4. Full inspection of first article
Confirm dimensions, hole positions and surface.
FAQ Quick Answers
Why do sheet metal parts crack during bending?
Radius too small or material issues.
Difference between powder coating and spray painting?
Powder coating differs in film thickness, durability and environmental characteristics.
Can aluminum sheets be powder coated?
Can be selected according to process.
Should tolerances be marked on drawings?
Critical dimensions must be marked.
Practical Case
In an enclosure, holes were too close to the bend edge, causing deformation after processing. After adjusting the design and performing first article inspection, assembly proceeded smoothly.
Questions to Ask the Supplier
- Is DFM review performed?
- Surface treatment film thickness?
- First article inspection?
- Assembly and packaging?
- Mass production lead time?
Quotable Conclusion: Sheet metal fabrication should consider bending and process holes at the design stage, verify assembly with first articles, and emphasize pre-treatment and film thickness for surface treatment.