DC01 or S355MC: which steel for your part?
Both are unalloyed steel, both rust, both weld well. The difference is in strength and in the thicknesses they come in. With us, the thickness usually decides: we cut DC01 from 1 to 2.5 mm and S355MC from 3 to 6 mm.
Side by side
| DC01 | S355MC | |
|---|---|---|
| Standard, material number | EN 10130, 1.0330 | EN 10149-2, 1.0976 |
| Made by | cold rolling | hot rolling, thermomechanical |
| Thicknesses with us | 1 to 2.5 mm | 3 to 6 mm |
| Yield strength | max 280 N/mm² | min 355 N/mm² |
| Tensile strength | 270 to 410 N/mm² | 430 to 550 N/mm² |
| Elongation at break | min 28 % | min 19 % |
| Weldable | yes | yes |
| Rusts | yes | yes |
What the difference means in practice
Yield strength is the load at which steel stays bent. For DC01 it is at most 280 N/mm², for S355MC at least 355 N/mm². A part in S355MC takes noticeably more before it stays bent.
DC01, in turn, is soft and easy to form. It bends tightly without cracking and has a smooth, even surface that paints well. That makes it the sheet for enclosures, covers and panels.
S355MC is a fine-grain structural steel for load-bearing parts. It can be cold formed too, but springs back more and needs a larger radius when bent.
Why thickness decides it with us
Cold rolled sheet like DC01 only goes up to 3 mm, and our supplier carries S355MC from 3 mm. So we split the two to meet without a gap: up to 2.5 mm we cut DC01, from 3 mm S355MC.
In practice you choose the thickness and the steel follows. If you need a strong part and 2.5 mm is not enough, S355MC at 3 mm is the next step.
Rust protection
Both steels arrive dry, without oil. That is handy for painting, but bare steel quickly picks up flash rust in damp air. If the parts are not coated right away, store them dry or oil them lightly.
Outdoors, both need powder coating, zinc plating or paint. If the part has to last outside without a coating, stainless steel or aluminium is the better choice.
Our recommendation
Covers, panels, enclosure parts, templates
DC01 at 1 to 2 mm. Inexpensive, smooth and easy to paint.
Mounting plates for devices up to about 20 kg
DC01 at 2 to 2.5 mm.
Parts you bend yourself
DC01, as long as 2.5 mm is enough. It bends tightly and without cracks.
Gusset plates, brackets under load, tabs
S355MC at 3 to 5 mm.
Base plates for posts, mounting plates for motors and pumps
S355MC at 4 to 6 mm.
Outdoors without a coating
Neither. Stainless steel 1.4301 or aluminium AlMg3.
These are rules of thumb for static loads. If a part carries people or a failure could cause harm, have someone do the calculation.
You see the price for every material before you order.