Technical Description and Scope of the JIS G3446 Standard
This Japanese Industrial Standard establishes technical requirements for stainless steel pipes intended for use in the mechanical engineering sector, automotive industry, bicycle production, furniture industry, as well as in the manufacturing of critical mechanical assemblies and structural components. The standard ensures the unification of quality and reliability parameters for products supplied by EV Group China.
The provisions of this standard are based on current regulatory documents. The application of products must comply with the latest editions of the following standards:
- JIS G 0320: Methods for heat analysis of steels.
- JIS G 0321: Product analysis and permissible variations.
- JIS G 0404: General requirements for delivery of steel products.
- JIS G 0415: Requirements for inspection documentation.
- JIS Z 2241: Tensile testing at room temperature.
- JIS Z 2243, 2244, 2245: Hardness testing standards (Brinell, Vickers, Rockwell).
- JIS Z 8401: Rules for rounding off numerical values.
The classification of pipes is based on 12 steel categories and technological production methods, presented in the table below.
| Classification | Steel Grade | Manufacturing Method | Finishing Treatment |
|---|---|---|---|
| Austenitic | SUS303TKA | Seamless: S; Automatic arc welding: A; Laser welding: L; Electric resistance welding: E | Hot-worked: H; Cold-worked: C; Electric resistance welded: G; Finished weld: B |
| SUS304TKA | |||
| SUS304LTKA | |||
| SUS316TKA | |||
| SUS316LTKA | |||
| SUS321TKA | |||
| SUS347TKA | |||
| SUS304TKC | |||
| SUS316TKC | |||
| Austenitic-Ferritic | SUS821L1TKA | ||
| SUS323LTKA | |||
| SUS329J1TKA | |||
| SUS329J3LTRA | |||
| SUS329J4LTKA | |||
| Ferritic | SUS405TKA | SUS430TKA | |
| SUS430TKC | |||
| SUS430LXTKC | |||
| SUS430J1LTKC | |||
| SUS436LTKC | |||
| SUS444TKA | |||
| SUS445J1TKC | |||
| Martensitic | SUS403TKA | ||
| SUS410TKA | |||
| SUS410TKC | |||
| SUS416TKA | |||
| SUS420J1TKA | |||
| SUS420J2TKA | |||
| SUS431TKA | |||
| SUS440CTKA | |||
| Precipitation Hardening | SUS630TKA | ||
| SUS631TKA |
Identification and Marking Requirements
Every product that has passed EV Group China’s factory quality control is subject to mandatory marking. For small-diameter pipes or upon specific customer request, marking may be applied to the packaging unit. Standard marking includes the steel grade designation, production process symbol, and geometric parameters (outer diameter and wall thickness).
Production process designation system:
- Seamless (hot-rolled/cold-rolled): S-H / S-C
- Automatic arc welding (basic, cold-rolled, finished weld): A / A-C / A-B
- Laser welding (basic, cold-rolled, finished weld): L / L-C / L-B
- Electric resistance welding (G-treated, cold-rolled): E-G / E-C