Q235 vs Q345 vs Q195 Carbon Steel: Grade Comparison for Buyers
When sourcing carbon steel from China, three grades dominate the conversation: Q235, Q345, and Q195. Each serves a different price-performance niche, and choosing the wrong one can cost you money or compromise structural integrity. This guide breaks down their mechanical properties, chemical composition, and ideal use cases so you can make an informed purchase decision.
1. What Are Q235, Q345, and Q195?
These are Chinese national standards (GB/T 700 and GB/T 1591) designating general structural and low-alloy steels. They are the domestic equivalents of international grades like S235JR, S355JR, and A36 — but with subtle differences that matter for export buyers.
- Q195 — Low-carbon mild steel, the most economical option.
- Q235 — The “workhorse” grade, balanced strength and cost.
- Q345 — Higher strength low-alloy steel, ideal for heavy loads.
2. Yield Strength and Tensile Strength Comparison
| Grade | Yield Strength (MPa) | Tensile Strength (MPa) | Elongation (%) |
|---|---|---|---|
| Q195 | ≥ 195 | 315–430 | ≥ 33 |
| Q235 | ≥ 235 | 370–500 | ≥ 26 |
| Q345 | ≥ 345 | 470–630 | ≥ 21 |
Q345 offers roughly 47% higher yield strength than Q235, making it the better choice for load-bearing structures. Q195 trades strength for ductility and cost savings.
3. Chemical Composition Breakdown
| Element | Q195 (max %) | Q235 (max %) | Q345 (max %) |
|---|---|---|---|
| C | 0.12 | 0.22 | 0.20 |
| Si | 0.30 | 0.35 | 0.55 |
| Mn | 0.50 | 1.40 | 1.70 |
| P | 0.035 | 0.045 | 0.035 |
| S | 0.040 | 0.050 | 0.035 |
4. Which Grade Should You Choose?
- Choose Q195 for wire rods, light frames, or non-structural sheet metal where cost is the priority.
- Choose Q235 for general construction, welded structures, machinery parts, and shipping containers. It is the default for 70% of Chinese export orders.
- Choose Q345 for bridges, cranes, pressure vessels, and offshore platforms where weight reduction or higher load capacity is required.
5. Price Difference and Sourcing Impact
On average, Q345 costs 8–15% more than Q235 per ton, while Q195 is 5–10% cheaper than Q235. If your project specification allows Q235, using Q345 is over-engineering. Conversely, substituting Q235 for Q345 in a high-stress design is a safety risk.
6. International Equivalent Standards
- Q235 ≈ S235JR (EN 10025) / A36 (ASTM)
- Q345 ≈ S355JR (EN 10025) / A572 Gr 50 (ASTM)
- Q195 ≈ S185 (EN 10025) / A283 Gr A (ASTM)
FAQ
Can Q235 replace Q345 in a structural design?
Only if the design load is recalculated and approved by a structural engineer. Never swap grades without recalculating safety margins.
Is Q195 weldable?
Yes, Q195 has excellent weldability due to its very low carbon content. It is widely used in welded wire mesh and light-gauge tubing.
Which grade is most common for export from China?
Q235 is the most exported grade, followed by Q345. Most Chinese mills stock Q235B as the default material.
Do these grades come with mill test certificates?
Yes, reputable mills provide GB/T-compliant MTCs. Huaxia-Steel includes third-party SGS or BV verification upon request.
Can I order mixed grades in one shipment?
Yes, but each grade must be clearly marked, segregated, and documented with separate MTCs to avoid customs or inspection issues.
Get a Quote for Q235, Q345, or Q195
Huaxia-Steel supplies all three grades with full mill certification, third-party inspection, and FOB/CIF shipping. Contact us for a competitive quote tailored to your specification.
