DC03, steel number 1.0347 under EN 10130, is the drawing-quality member of the cold rolled DC family. It sits between the general forming grade DC01 and the deep drawing grade DC04, and that position makes it a very practical choice: it stretches and draws far better than DC01, yet costs less than DC04 because the chemistry and the rolling practice are less demanding. Automotive and appliance manufacturers use DC03 in large volumes for parts that are drawn, stretched and painted, and this article explains the data behind that choice and where the grade is applied.
Chemical Composition of DC03
The grade is a low carbon, unalloyed steel with these guaranteed maxima under EN 10130:
| Element | Max % |
|---|---|
| Carbon (C) | 0.10 |
| Manganese (Mn) | 0.45 |
| Phosphorus (P) | 0.035 |
| Sulphur (S) | 0.035 |
The tighter carbon and manganese ceilings relative to DC01 reduce work hardening during deformation, which is the physical reason DC03 draws further before the material stiffens and tears.
Mechanical Properties of DC03
| Property | Value |
|---|---|
| Yield strength Re (MPa) | 140 - 240 |
| Tensile strength Rm (MPa) | 270 - 370 |
| Elongation A80 (min %) | 34 |
Compared with DC01, the elongation guarantee rises from 28% to 34% and the yield band narrows from 140 - 280 to 140 - 240 MPa. DC03 also carries improved plastic strain ratio and strain hardening values in the standard test thickness ranges, which is the formal signal that the sheet is certified for drawing work rather than simple bending.
Why DC03 Suits Automotive Deep Drawing
In vehicle manufacture, the material is specified for components that are drawn in multi-stage dies but do not demand the highest ductility of DC04 or DC05. Typical parts include floor pan reinforcements, wheel housing inners, seat frames, door inners, dash panel structures, oil pan shells and battery trays. Two properties matter on the press line: consistent yield behaviour across the coil, which keeps springback predictable, and clean surface quality, because automotive parts are painted to Class A appearance or are visible after assembly. DC03 delivers both without the cost premium of the deeper drawing grades, and its softness keeps die wear moderate.
Why DC03 Fits Home Appliance Complex Forming
White goods production is the other large consumer. Washing machine tubs and drums, dryer front panels, refrigerator door panels, microwave oven inner boxes, dishwasher liners and air conditioner housings are all drawn, flanged and pierced from cold rolled coil, and DC03 gives the forming margin those geometries need while remaining compatible with enamelling, painting and powder coating. For appliance parts that are only bent or lightly stamped, DC01 is cheaper; for the deepest draws, DC04 or DC05 take over. DC03 occupies the middle band where a drawn shape still has straight wall sections and modest draw ratios.
DC01 vs DC03 vs DC04: Selection Guide
| Grade | Elongation A80 (min %) | Typical parts | Relative cost |
|---|---|---|---|
| DC01 | 28 | Brackets, covers, light stampings | Lowest |
| DC03 | 34 | Drawn panels, tubs, inner structures | Mid |
| DC04 | 38 | Deep cups, complex shells | Highest |
The rule for the buyer is to match the grade to the deepest deformation in the part. If a prototype tears or necking appears at the corners, the answer is one step up the ladder, not a change of tooling philosophy.
Frequently Asked Questions
What is the steel number of DC03?
DC03 is material number 1.0347 in the European steel numbering system, and it is specified in EN 10130 as a drawing-quality cold rolled low carbon steel for cold forming.
How is DC03 different from DC01?
DC03 has a lower carbon ceiling, 0.10% versus 0.12%, and a higher minimum elongation, 34% versus 28%, with a tighter yield band. In practice, DC03 draws and stretches reliably where DC01 would thin locally and split in a deep die.
Is DC03 cheaper than DC04?
Usually yes. DC04 requires an even lower carbon limit, 0.08%, and more demanding rolling and annealing control, so the mill cost is higher. When the draw ratio is moderate, DC03 is the economic way to buy forming margin without paying for deep drawing grade.
Can DC03 be used for painted exterior panels?
Yes. Ordered with surface class A or B and a clean, oiled finish, DC03 takes paint and powder coating to a high appearance standard. Appliance manufacturers rely on it for visible panels precisely because the surface and the forming response are consistent.
Does DC03 work for enamelling?
It is one of the standard enamelling substrates in appliance production because the low carbon content resists fish-scaling in porcelain enamel firing. The enamel supplier should confirm the required carbon and surface specification for the specific enamel system.
What thickness range is typical for DC03 coil?
EN 10130 applies up to about 3 mm, and the common appliance and automotive range is 0.5 to 2.5 mm. Thickness groups change the guaranteed elongation slightly, so the certificate should be checked against the ordered thickness.