Common Quality Grades (Automotive)?
JR: Room Temperature Impact (20℃), General Purpose Parts
J0: 0℃ Impact, Chassis Parts
J2: -20℃ Impact, Safety/Cold Region
MC: Cold Forming Dedicated
Thickness Direction Performance (Z-direction)?
For thick plates (>15mm), S355J2+Z15/Z35 is available, providing protection against lamellar tearing (frame/support).
Surface Quality Requirements?
Automotive Grade: No cracks/scars/inclusions, pickled plate roughness Ra≤10μm.
S355 Lightweighting Effect?
15–20% thinner and lighter than Q235, with increased rigidity.
Cost Comparison (Automotive)?
S355 is 10–15% more expensive than Q235, but the overall cost is lower due to weight reduction, less material usage, and longer lifespan.