Process comparison
Thermoforming vs Sheet metal
Sheet-metal covers and enclosures are cut, bent, welded and painted; thermoformed plastic parts are formed in one piece from coloured sheet. For many covers and housings, converting to plastic cuts weight, cost and corrosion.
Thermoforming vs Sheet metal — side by side
| Thermoforming | Sheet metal | |
|---|---|---|
| Weight | Light | Heavy |
| Corrosion | None — will not rust | Rusts without coating |
| Tooling / setup | Low-cost soft tooling | Dies, fixtures, welding jigs |
| Finishing | Colour formed in — no paint | Deburr, paint or plate |
| Part consolidation | Several parts into one | Cut/bend/weld multiple pieces |
| Best volume | Low to medium | Any, but labour-heavy at low volume |
Choose Thermoforming when…
- Covers, guards, enclosures and panels
- Weight, corrosion or paint elimination matter
- Consolidating a welded assembly into one formed part
Choose Sheet metal when…
- Load-bearing structural members
- Very high-temperature or EMI-critical parts (unless shielded)
- Parts needing metal stiffness in thin sections
The verdict: For non-structural covers, guards and enclosures, converting sheet metal to thermoformed plastic cuts weight, removes corrosion and paint, and consolidates parts — usually at lower tooling cost. Structural, high-temperature or EMI-critical parts may stay metal.
Frequently asked
Is plastic strong enough to replace metal?
Often, yes — with the right grade and design. Thick-gauge thermoforming makes rigid parts, and stiffness is engineered in with wall thickness, ribs and formed geometry.
Can plastic parts be EMI-shielded?
Yes — conductive coatings or shields can be added where enclosures need EMI/RFI performance.
Not sure which fits?
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