SPCC, stainless steel and aluminium all appear on enclosure drawings, and the choice is usually made for reasons that have nothing to do with price: where the cabinet is installed, how it is finished and what it has to weigh. This page compares the three on the points that decide the outcome.
Choosing Material by Application, Not by Preference
The useful question is not which material is best but which one suits the installation. An indoor cabinet painted and mounted in a plant has different requirements from an outdoor cabinet on a coastal site, and the material callout should follow that difference.
Comparing the Three Common Choices
| SPCC (cold-rolled carbon steel) | The default for painted indoor cabinets and general fabrication. It forms and welds predictably, takes powder coating well, and is the most economical of the three. It has no corrosion resistance of its own, so the coating is doing all the work. |
|---|---|
| SECC / SGCC (zinc-coated steel) | Carbon steel with a galvanised surface. Better corrosion behaviour where the coating is scratched or where edges are exposed, and a common choice for outdoor enclosures. Welding burns the zinc locally, so joint areas need treatment and the fumes need extraction. |
| SUS304 stainless steel | Chosen where corrosion resistance, hygiene or appearance matters: outdoor and coastal installations, food and medical equipment, washdown areas. It is heavier, harder to form, and the material cost is several times that of carbon steel. |
| Aluminium | Chosen for weight, for heat dissipation, or where a bright anodised finish is wanted. It cannot be welded to steel, needs different tooling and fasteners, and it marks more easily in handling. |
What Changes Once the Material Changes
Material choice is not a single substitution. Changing from SPCC to SUS304 changes the bend allowance, the required tooling, the welding process and the post-weld treatment, and it can change the minimum bend radius for the same thickness. Changing to aluminium changes the hardware: self-clinching inserts designed for steel may not hold in a softer sheet, and galvanic contact between aluminium and steel has to be considered at every fixing point.
Those consequences are why material is confirmed at the drawing review stage rather than after the first article, and why a substitution made to save cost is checked against the assembly rather than against one part.
Mixing Materials in One Assembly
Mixed-material assemblies are common and perfectly workable, provided the interfaces are specified: isolated fixings or plated hardware where two different metals meet, and a finish schedule that does not leave a bare steel edge against stainless. Where the drawing is silent and the environment is corrosive, we raise it as a question.
What Actually Changes in Cost and Timing
Material cost is only one line in the quotation. A heavier or harder material changes the cutting time, the tooling, the number of operations and the amount of scrap, and stainless steel usually needs a post-weld treatment step that carbon steel does not. The honest comparison is therefore between complete process routes, not between two material prices.
The same applies to sourcing: carbon and galvanised steel are widely stocked, while a specific stainless grade or an unusual aluminium alloy is ordered per project and carries its own lead time. Stating the material in the RFQ, rather than leaving it to be confirmed after the order, is what keeps the quoted date achievable.
SPCC vs Stainless Steel: Common Buyer Questions
Which material is best for an outdoor enclosure?
It depends on the environment and the service life expected. Galvanised steel with a powder coat is a common and economical answer for general outdoor use. Stainless steel is chosen where the installation is coastal, where washdown chemicals are used, or where the coating cannot be maintained.
Can you supply material certificates?
Yes. Mill certificates are available with the batch for the material used, and where the certificate matters for your own documentation, say so in the RFQ so it is included in the quotation.
Does material choice change the lead time?
It can. Carbon and galvanised steel are the fastest to source. Stainless and aluminium depend on the grade and thickness, and non-standard grades are ordered per project. The route and timing are confirmed in the quotation.
Send the SPCC vs Stainless Steel Drawing Package
For a useful quotation, send drawings, quantity, material, finish and assembly requirements. Violet Gao will review your project and reply with technical feedback.
Request a QuoteWhat stands behind this quotation
- Manufacturing since 20162,500 m² Ningbo plant — 3 laser cutting machines (including newer TRUMPF), 4 CNC press brakes and 10 welding stations.
- Shipped to more than 30 export marketsEnclosures, cabinets and formed parts supplied to OEM buyers across Europe, North America and Asia.
- 123 documented product casesMedical device housings, HVAC and heat pump enclosures, agricultural and livestock equipment, industrial hydraulics, material handling trolleys and EV charging cabinets.
- Factory evidence you can checkTUV Rheinland audit reference MIC-ASI243729 and Bureau Veritas reference MIC-ASR263630 available for buyer review under NDA.
Before you send drawings: an NDA is signed on request · first-article inspection is carried out before a batch continues · pricing is staged from prototype quantity to repeat volume · pre-shipment photos and packing records are prepared when the project needs them.