SPCC, DC01, St12, JSC270C, A1008-CS and CR1 are different names for the same family of steel: commercial-quality cold-rolled low-carbon steel. Each name comes from a different standard system, JIS G3141 in Japan, EN 10130 in Europe, DIN 1623 in Germany, JFS A2001 in the Japanese automotive industry, ASTM A1008 in North America and the CR designation in international stamping practice, but they describe the same level of formability. Understanding the family helps buyers translate a drawing from one system to another and order the right material the first time.
The formability family from CQ to SEDDQ
The cold-rolled formability grades are arranged in steps from commercial quality up to super extra deep drawing quality. Each step adds guaranteed formability at the price of more careful steelmaking. The table below shows the standard mapping, including the CR class used by automotive and stamping buyers.
| Formability | JIS G3141 | EN 10130 | DIN 1623 | JFS A2001 | ASTM A1008 | CR class |
|---|---|---|---|---|---|---|
| Commercial (CQ) | SPCC | DC01 | St12 | JSC270C | CS | CR1 |
| Drawing (DQ) | SPCD | DC03 | RSt13 | JSC270D | DS | CR2 |
| Deep drawing (DDQ) | SPCE | DC04 | St14 | JSC270E | DDS | CR3 |
| Extra deep drawing | SPCEN | DC05 | St15 | JSC270F | EDDS | CR4 |
| Super extra deep drawing | - | DC06 | St16/St17 | JSC270G | - | CR5 |
Standards behind the names
Each designation is defined in its own standard, and the standards differ in what they guarantee. JIS G3141 specifies chemical composition and mechanical properties for SPCC, SPCD and SPCE, with thickness-dependent elongation. EN 10130 specifies chemistry, yield, tensile and elongation for DC01 to DC06, and is the system most European buyers quote. DIN 1623 is the traditional German sheet standard, still widely used in specifications. JFS A2001 is the Japan Federation standard used by Japanese automakers and their suppliers. ASTM A1008 covers the CS, DS, DDS and EDDS grades for North America, and ISO 3574 is the international standard for commercial and drawing quality cold-reduced sheet. When a drawing cites one system, the equivalent grade in another system is usually acceptable if the mechanical values are confirmed against the actual application.
Thickness, width and delivery range
This product family is supplied as coils in the practical range of 0.25-3.0 mm thickness and 600-2150 mm width, with an inner diameter of 508 or 610 mm depending on the processing line. The strip is annealed and skin-passed, and can be delivered with a mill edge or trimmed edge, dry or oiled. For stamping lines, the most important property is the consistency of mechanical values from coil to coil: ask for the mill certificate with each coil and record the yield and r-value so that tooling and press settings can be kept stable.
High-strength cold-rolled options
When the application needs strength above the mild-steel family, cold-rolled high-strength steels are ordered from their own families: the SPFC series per JIS G3135, the HX series per EN 10268, and bake-hardening grades that gain strength in the paint oven, for example JSC270H and JSC340H in the JFS system and H180B-type grades in the EN system. Dual-phase and complex-phase grades cover the upper strength range for structural automotive parts. These grades are not equivalents of the CQ to SEDDQ family; they are a separate product family with their own chemistry, and should be specified by standard and grade number, not by translation.
Frequently asked questions
1. Are SPCC, DC01, St12, JSC270C and A1008-CS the same steel?
They are equivalents at the same formability level, commercial quality, from different standard systems. They share similar chemistry limits and mechanical values, but each is certified to its own standard, so order to the system your customer requires.
2. What does CR1 mean?
CR1 is the commercial-quality class in the CR designation used by automotive and stamping buyers, equivalent to SPCC, DC01, St12, JSC270C and A1008-CS. The sequence CR1 to CR5 follows increasing formability.
3. What is the difference between CQ and DDQ?
Commercial quality is for bending and simple forming. Drawing quality and deep drawing quality add lower carbon, lower yield and higher elongation guarantees for drawn parts. Choose the lowest class that passes the forming trial.
4. Which standard should I use for an automotive drawing?
Use the system the customer specifies, usually JFS A2001 for Japanese OEMs, EN 10130 for European, or ASTM A1008 for North American. Confirm the mechanical values with the mill before ordering.
5. What thickness range is available?
Coils are available in 0.25-3.0 mm thickness and 600-2150 mm width, with 508 or 610 mm inner diameters.
6. When do I need a high-strength cold-rolled grade?
When the part must carry load or resist denting beyond what mild steel provides. Use the SPFC series per JIS G3135, the HX series per EN 10268, or bake-hardening grades, specified by standard and grade rather than by equivalence.