DC01 to DC05 Cold Rolled Steel Coils: Grade Selection for Forming and Decorative Applications

Cold rolled steel coils in the DC01 to DC05 range cover almost every light forming job in the sheet metal industry, from simple brackets to multi-stage deep drawn housings. Because the five grades share one standard, EN 10130, their behaviour is predictable and their test data comparable. This article explains how the grades differ, when to move up the series, and how to avoid the specification confusion that appears when a decorative stainless steel requirement is mixed into a DC carbon steel enquiry.

How the DC Series Is Structured

The number in the designation is the forming rank. DC01 is the general purpose member, DC02 no longer appears in current EN 10130 editions and has been absorbed into the DC01 supply practice, DC03 is the drawing grade, DC04 the deep drawing grade, and DC05 the extra deep drawing grade. Above them, DC06 and DC07 serve extreme drawing. Each step down the carbon and manganese content and each step up the guaranteed elongation widens the range of deformation the sheet can accept without tearing.

Chemical Composition Across the Grades

Mechanical Properties and What They Mean for Tooling

In practice, the yield strength band also shifts downward as the grade improves. A lower and tighter yield range means the material stretches more uniformly before local thinning, which is exactly what a die designer needs for a part with a draw ratio above about 1.8. Moving from DC01 to DC04 can raise tooling-friendly elongation from 28% to 38% while the tensile strength stays below 350 MPa, so the press load requirement does not climb with formability.

Decorative Applications and the Stainless Steel Confusion

For decorative sheet metal work such as trim panels, lighting housings, furniture profiles and interior cladding, DC01 and DC03 coils are popular because they paint, powder coat and laminate well. One recurring error is a request that mixes DC carbon grades with a stainless grade such as 201 in the same specification line. The DC series is carbon steel and cannot deliver stainless corrosion performance. If the decorative part must resist rust in humid service, the specification should be moved to an austenitic or ferritic stainless grade such as 201 or 430 under the relevant stainless standard, not to a higher DC number. A higher DC grade only buys formability, never corrosion resistance.

Selecting Thickness for Coil Orders

Common coil thicknesses such as 1.0 mm, 1.2 mm and 2.5 mm each sit in different EN 10130 test groups, so the mechanical guarantees apply per the thickness actually ordered. Thin material below 0.7 mm has its own elongation tables, and thick material above 3.0 mm falls outside the standard scope altogether. When a quote is received, verify that the mechanical values on the mill test certificate correspond to the ordered thickness group, not to the thickest row of the standard table.

Frequently Asked Questions

What is the difference between DC01 and DC04?

DC04 has markedly better deep drawing behaviour: elongation rises from 28% to 38% and the yield band narrows to 140 - 210 MPa, so the sheet distributes strain more evenly. DC01 is the economic choice for simple bending and shallow stamping; DC04 is specified when the die draws a deep cup or a complex shell.

How does DC04 compare with DC05?

DC05 lowers the tensile ceiling to about 330 MPa and raises minimum elongation to 40%, which suits very deep drawn parts and severe stretching. DC06 and DC07 extend the same principle for the most extreme automotive and appliance components, with elongation of 41% and above.

Can DC coils be supplied with a metallic coating?

Yes. The same base chemistries are the substrates for continuously galvanized and aluminium-zinc strip: DX51D, DX53D and DX54D under EN 10346 mirror DC01, DC03 and DC04 forming levels respectively, with a hot-dip zinc or aluminium-zinc coating added.

Is DC02 still a valid grade?

In current EN 10130 editions the grade list runs DC01, DC03, DC04 and above; DC02 has effectively disappeared from modern supply. A request for DC02 should be confirmed against the actual application, because suppliers will normally propose DC01 or DC03 depending on the forming severity.

Which grade should I choose for a decorative panel that will be painted?

DC01 with surface class A or B is the standard answer: it forms cleanly, paints evenly, and keeps cost low. Specify surface class and oiling in the order, because a high-gloss painted panel tolerates no surface blemishes from the coil supplier.

Do DC grades work for welding and subsequent coating?

All five grades weld easily with conventional methods thanks to low carbon content. After welding, edges and weld zones should be cleaned before painting to avoid oxide contamination, and if the finished part is to be hot-dip galvanized, the DC01 to DC03 softness is preferred for a uniform coating response.