Japan vs China Ferrous Metal Standards: Steel Grade Comparison Table
When sourcing steel and alloy materials internationally, understanding the equivalent grades between Japan (JIS) and China (GB) standards is essential for engineers, procurement teams, and manufacturers. This comparison table provides a quick reference for ferrous metal grades commonly used in structural components, mechanical parts, bolts, nuts, and specialized applications.
In structural steels, SS400 in Japan is roughly equivalent to Q235-A in China, offering similar tensile strength and weldability for construction and general engineering. For higher strength applications, SM490B corresponds to Q345B, which provides improved yield strength and toughness.
For spring steels, SUP3 matches 65Mn, widely used for leaf springs and resilient components. Alloy steels such as SCM440 (QT) in Japan align with 42CrMo in China, both offering excellent hardness and fatigue resistance after quenching and tempering. Similarly, S45C corresponds to 45 steel, available in both normalized (N) and quenched and tempered (QT) conditions.
In cast iron, FCD45 is equivalent to QT450-10, providing good machinability and wear resistance. For bolts and nuts, Japanese grades 6T/4T or 10T correspond to Chinese high-strength bolt standards like 8.8 and Grade 9–10.
These equivalents help ensure compatibility in design, manufacturing, and replacement parts. Selecting the right material not only ensures compliance with mechanical property requirements but also streamlines global procurement.
Summary Table:
| Japan Standard | China Standard | Notes |
|---|---|---|
| SS400 | Q235-A | Structural steel |
| SM490B | Q345B | Higher strength |
| SUP3 | 65Mn | Spring steel |
| SCM440 (QT) | 42CrMo | Quenched & tempered |
| S45C (N/QT) | 45 | Normalizing / Q&T |
| FCD45 | QT450-10 | Cast iron |
| 6T / 4T | 8.8 | Bolt & Nut |
| 10T | Grade 9–10 | High-duty bolts |
Understanding these Japan–China ferrous metal equivalents enables better engineering decisions, reduces procurement risks, and ensures material consistency across international projects.
|
Japan |
China |
Notes |
Japan |
China |
| SS400 | Q235-A | SUP3 | 65Mn | |
| SM490B | Q345B | SUP3(SUP6-13) | 50CrVA | |
| SCM440（QT） | 42CrMo | quenching and tempering | SS400(SS41) | Q235-A |
| LBc3 | ZQSn10-5 | Q235-B | ||
| S45C(N) | 45 | normalizing | Q235-C | |
| S45C(QT) | 45 | quenching and tempering | Q235-D | |
| FCD45 | QT450-10 | SCM415 | 20CrMnTi | |
| SCM435（QT） | 35CrMo | quenching and tempering | SCM435 | 35CrMo |
| SM58Q | 15MnV | SCM440 | 42CrMo | |
| 6T,4T | 8.8 8 | BOLT &NUT | SCr420 | 20Cr |
| SCW410 | ZG230-450 | SCr440 | 40Cr | |
| 10T | High Duty Bolt | Grade 9-10 | S20C | 20 |
| S25C | 25 | |||
| S35C | 35 | |||
| S45C | 45
|
