What is JAC series steel?
JAC series steel (JFS standard) is a high-performance cold-rolled & galvanized automotive steel family including JAC270C/D/E/F, JAC340H, JAC440W, JAC590R, covering commercial forming, deep drawing, high-strength structural and ultra-high-strength applications. It delivers balanced formability, strength, corrosion resistance and weldability, widely used in vehicle body, chassis and safety components.
Automobile Factory
JAC Series Steel: Chemical Composition (JFS Standard)
| Grade | C (%) | Mn (%) | P (%) | S (%) | Si (%) | Al (s) (%) | Key Alloying |
|---|---|---|---|---|---|---|---|
| JAC270C | ≤0.12 | 0.30–0.60 | ≤0.035 | ≤0.035 | ≤0.05 | ≥0.015 | - |
| JAC270D | ≤0.10 | 0.25–0.50 | ≤0.030 | ≤0.030 | ≤0.05 | ≥0.020 | - |
| JAC270E | ≤0.08 | 0.20–0.45 | ≤0.025 | ≤0.025 | ≤0.05 | ≥0.020 | - |
| JAC270F | ≤0.06 | 0.15–0.40 | ≤0.020 | ≤0.020 | ≤0.05 | ≥0.020 | - |
| JAC340H | ≤0.12 | 0.80–1.40 | ≤0.030 | ≤0.030 | ≤0.10 | ≥0.015 | Ti/Nb (microalloy) |
| JAC440W | ≤0.10 | 1.00–1.60 | ≤0.025 | ≤0.025 | ≤0.15 | ≥0.015 | Ti/Nb |
| JAC590R | ≤0.08 | 1.50–2.20 | ≤0.020 | ≤0.020 | ≤0.20 | ≥0.015 | Ti+Nb+Mo |
Notes:
Low C & impurity control for excellent formability & surface quality
Ti/Nb for fine grain & precipitation strengthening (high-strength grades)
Conforms to JFS A2001 (cold-rolled) / JFS A3011 (galvannealed)
Mechanical Properties (Typical Range, t=0.4–3.2mm)
| Grade | Yield Strength (MPa) | Tensile Strength (MPa) | Elongation (A80, %) | r-value (min) | Grade Character |
|---|---|---|---|---|---|
| JAC270C | 175–275 | ≥270 | 34–50 | 1.2 | Commercial forming |
| JAC270D | 160–260 | ≥270 | 38–52 | 1.3 | Drawing quality |
| JAC270E | 150–250 | ≥270 | 42–55 | 1.4 | Deep drawing |
| JAC270F | 140–240 | ≥270 | 45–58 | 1.5 | Extra deep drawing |
| JAC340H | 300–380 | ≥340 | 28–38 | 1.1 | High-strength structural |
| JAC440W | 380–460 | ≥440 | 22–32 | 1.0 | High-strength |
| JAC590R | 520–600 | ≥590 | 16–24 | 0.9 | Ul |
Size & Coating Specifications
Thickness: 0.4–3.2 mm
Width: 800–1800 mm
Coating: Hot-dip Zn–Fe alloy (galvannealed/ZF)
Coating weight: 60–440 g/m² (double-sided)
Surface: Oiled (O), passivated (FD), chromated (FC), BNA, bright/rough
Product: Coil, strip, cut sheet
Core Characteristics of JAC Series Steel
4.1 Graded Formability (270 Series)
C: General stamping (doors, hoods)
D: Moderate drawing (inner panels)
E: Deep drawing (complex shells)
F: Extra deep drawing (severe deep draw parts)
High r-value (1.2–1.5) → uniform deformation, no cracking/wrinkling
4.2 High Strength (340H/440W/590R)
JAC340H: Structural parts (floor, cross members)
JAC440W: Chassis & safety components
JAC590R: Crash parts, reinforcements (ultra-high strength)
Weight reduction vs mild steel: 15–30% while maintaining safety
4.3 Excellent Galvannealed (ZF) Coating
Zn–Fe alloy: better paint adhesion & weldability than pure Zn
Corrosion resistance: 2–3× uncoated steel
Smooth surface for auto outer panels
4.4 Weldability & Processability
Low carbon → stable resistance/MIG/TIG welding
Consistent batch quality for automated stamping lines
Compatible with cutting, slitting, bending, flanging
4.5 Standardization & Compatibility
JFS standard: global auto supply chain (Toyota, Honda, Nissan)
Clear grade ladder: from forming to ultra-high-strength
Equivalent to JSC270C/D/E/F, DC03–DC06, St14–St16
Typical Applications
JAC270C/D/E/F: Body panels, interiors, appliance shells
JAC340H: Floor pans, seat frames, structural brackets
JAC440W: Chassis, door beams, fuel tank shields
JAC590R: Bumpers, crash pillars, safety reinforcements
FAQ (JAC Series Automotive Steel)
1.What's the difference between JAC270C/D/E/F?
Formability increases: C (commercial) < D (drawing) < E (deep drawing) < F (extra deep drawing), with lower C & higher elongation.
2.Is JAC270F good for very deep drawing?
Yes. Highest r-value (≥1.5) & elongation (45–58%) for severe deep drawing without fracture.
3.What's JAC340H used for?
High-strength structural parts (floor, cross members) needing strength + moderate formability.
4.What does "W" mean in JAC440W?
W = high-strength with good weldability & formability balance.
5.What's JAC590R?
Ultra-high-strength (≥590MPa) for crash safety components; precipitation hardened (Ti/Nb/Mo).
6.Coating options for JAC steel?
Hot-dip Zn–Fe (ZF) 60–440g/m²; surfaces: oiled, passivated, chromated, BNA.
7.Can JAC steel be welded?
Yes. Low C & optimized composition for resistance, MIG, TIG welding.
8.What standards apply?
JFS A2001 (cold-rolled), JFS A3011 (galvannealed auto steel).
GNEE's Partners
