The core trade-off
Mild steel (MS) costs less as raw material and is easier to weld and shape, which is why it's still widely used, especially when the piece will be painted or powder-coated. Stainless steel costs more upfront but doesn't rust and needs no repainting — the value shows up over years, not on day one.
Where MS still makes sense
- Budget-constrained projects where upfront cost is the deciding factor
- Heavily painted/coated work where the coating, not the steel, defines the final look
- Purely structural elements hidden from view and weather
Where stainless steel earns its cost
- Anything exposed to weather or humidity long-term (MS will eventually rust through paint, especially at welds and edges)
- High-touch fixtures like handrails, where a consistent finish matters
- Anywhere repainting access is difficult or expensive over the building's life
A middle ground
Some projects use MS for the hidden structural frame and stainless for exposed, visible or handled surfaces — a reasonable way to control cost without giving up durability where it's actually seen and touched. Discuss this hybrid approach with your fabricator if budget is tight.