DC03 is a non-alloy quality steel of the deep-drawing class, designated with material number 1.0347 in the European numbering system. It sits between DC01, the general forming grade, and DC04, the highest-volume deep-drawing grade, and it is chosen when a part is drawn or profiled with enough severity that DC01 is not reliable, but where the extreme ductility of DC04 is not yet needed. This article explains the material on the basis of the standards that govern it, the chemical and mechanical values, and the equivalent designations used in other markets.
Standards that apply to DC03
DC03 appears in several European standards covering different product forms. EN 10130 covers cold-rolled low-carbon flat products for cold forming, which is the main reference for sheet and strip in general supply. EN 10139 covers cold-rolled uncoated mild steel narrow strip for cold forming, used when the product is slit to narrow widths. EN 10152 covers electrolytically zinc-coated cold-rolled flat products, where the same base steel receives an electro-galvanized coating. EN 10271 covers electrolytically zinc-nickel coated flat products. The buyer should name the product form and the matching standard in the order, because the coating and the dimensional tolerances differ between them.
Chemical composition limits
The chemical limits for DC03 are set to keep the steel soft and formable: carbon 0.10% maximum, manganese 0.45% maximum, phosphorus 0.035% maximum and sulphur 0.035% maximum. The low phosphorus and sulphur keep the steel free from segregation and inclusions that would tear during drawing, and the low carbon keeps the yield strength down. The steel is fully killed and, for the deep-drawing variants, treated so that it resists strain aging. These are maximum values; mill certificates typically report the actual ladle analysis, which is normally well inside the limits.
Mechanical properties
For flat product thicknesses above 0.5 mm up to 3.0 mm, EN 10130 defines the mechanical values for DC03 as follows: yield strength Rp0.2 of 140-240 MPa, tensile strength Rm of 270-370 MPa and minimum elongation A80 of 34%. The narrow yield band is the practical benefit of the grade: a press shop can predict springback and wall thinning closely, and the minimum elongation of 34% supports multi-stage drawing without intermediate annealing in most designs. The r and n values, the formability indices, are not guaranteed for DC03 in the same way as for the IF-steel grades, so for the deepest draws DC04, DC05 or DC06 should be considered.
| Property | DC03 / 1.0347 |
|---|---|
| Material number | 1.0347 |
| Classification | non-alloy quality steel, deep-drawing quality |
| Carbon max | 0.10% |
| Manganese max | 0.45% |
| Yield Rp0.2 | 140-240 MPa |
| Tensile Rm | 270-370 MPa |
| Elongation A80 min | 34% |
Equivalent grades
In British practice the closest equivalent is CR3, which corresponds to the same deep-drawing quality; CR4 maps to DC01 and lower numbers such as CR1 and CR2 to the deeper-drawing grades of the family. In German nomenclature the older designation St13 is frequently quoted for the same class, and in the Japanese system SPCD occupies a similar position as the drawing-quality cold-rolled grade. These equivalences are commercial guides, not legal substitutions: the contract should name the governing standard, because tolerances, testing and certification differ between systems.
Applications and forming behaviour
DC03 is used wherever a drawn or profiled part needs reliability at reasonable cost: automotive inner panels and brackets, appliance bodies and liners, office furniture components, and pressed parts for electrical enclosures. The material profiles and flanges cleanly, holds sharp radii without cracking at normal draw ratios, and delivers a good surface for painting after proper cleaning. When the part is to be galvanized, the coated equivalent in EN 10346 is the DX53D family for drawing work; when the part is uncoated and painted later, DC03 in EN 10130 is the direct specification.
Sourcing and verification checklist
State the standard and its edition, the grade DC03 or material number 1.0347, the thickness and width with tolerance class, the surface quality and the oiling requirement. Before shipment, request the mill certificate and verify the yield and tensile values against the 140-240 MPa and 270-370 MPa bands, the minimum elongation of 34%, and the chemical analysis. Check the edge quality after slitting, because slitting burrs propagate into drawing cracks, and confirm that the packaging protects the surface from condensation in transit.
Frequently Asked Questions
What does the material number 1.0347 mean? It is the designation of DC03 in the European steel numbering system, a unique identifier for the grade that is recognised across standards and databases.
What is the difference between DC01 and DC03? DC03 has a lower carbon limit of 0.10%, a lower yield band of 140-240 MPa and a higher minimum elongation of 34%, against 0.12%, 140-280 MPa and 28% for DC01; DC03 is the drawing-quality step above DC01.
Is DC03 suitable for deep drawing? Yes, for normal deep-drawing work; the 34% minimum elongation and narrow yield band support multi-stage draws. For the most severe draws, step up to DC04 or DC05, which guarantee r and n values.
Which standard should I order DC03 to? EN 10130 for cold-rolled sheet and wide strip, EN 10139 for narrow strip, and EN 10152 or EN 10271 for the electro-coated versions; name the product form and the standard in the order.
What is the British equivalent of DC03? CR3 is the commonly quoted British equivalent of DC03; CR4 corresponds to DC01 and lower numbers such as CR1 and CR2 to the deeper-drawing grades.
Can DC03 be electro-galvanized? Yes, EN 10152 covers the electro-zinc coated version of the same base steel, and EN 10271 covers the zinc-nickel coated version for higher corrosion resistance in thin coatings.