Two Names, Two Standards
When sourcing stainless steel fasteners globally, you may encounter two designations that appear similar but originate from different standardization systems: 304 and 1Cr18Ni9Ti. Understanding the distinction is essential for correct material specification and procurement.
304 (also written as AISI 304 or SUSU304) is the shorthand used in American (ASTM/AISI) and Japanese (JIS) standards, and has been widely adopted by domestic steel mills worldwide. 1Cr18Ni9Ti is the designation under the Chinese national standard (GB), and it represents a titanium-stabilized variant of the 18-8 austenitic stainless steel family.
Chemical Composition Comparison
While both grades belong to the austenitic stainless steel family, their chemical compositions differ in several key elements:
| Element | C (max) | P (max) | Cr | Ti |
|---|---|---|---|---|
| 06Cr19Ni10 (304) | 0.08% | 0.045% | 18–20% | — |
| 1Cr18Ni9Ti | 0.12% | 0.035% | 17–19% | (C×5−0.02)–0.80% |
The most notable differences are:
- Carbon content: 1Cr18Ni9Ti allows up to 0.12% carbon, compared to 0.08% for 304. Higher carbon can slightly reduce corrosion resistance in sensitization-prone environments.
- Chromium range: 304 has a slightly higher minimum chromium content (18%), contributing to better overall corrosion resistance.
- Titanium addition: 1Cr18Ni9Ti contains titanium as a stabilizing element, which prevents intergranular corrosion at elevated temperatures by binding excess carbon.
Performance Characteristics
The compositional differences translate into distinct performance profiles suited to different applications:
- 304 (06Cr19Ni10) offers superior corrosion resistance and toughness, making it the preferred choice for low-temperature applications and cold-forming processes such as thread rolling and stamping. It is the global standard for general-purpose stainless steel fasteners.
- 1Cr18Ni9Ti exhibits better thermoplasticity and machinability at elevated temperatures, making it well-suited for high-temperature service environments and turning/machining operations.
Which Grade Should You Specify?
For most standard fastener applications — including socket head cap screws, hex bolts, washers, and nuts — 304 stainless steel is the recommended specification due to its superior corrosion resistance, global availability, and compatibility with cold-forming manufacturing processes.
If your application involves sustained high-temperature exposure or requires enhanced resistance to intergranular corrosion in welded assemblies, 1Cr18Ni9Ti or its Western equivalent 321 stainless steel may be more appropriate.
FULLERKREG Material Expertise
At FULLERKREG, we supply stainless steel fasteners to DIN, ISO, and GB standards across both 304 and 316 grades, with full material traceability and mill certifications available on request. Our engineering team can assist with grade selection, cross-referencing between international standards, and sourcing for specialized applications.
Contact FULLERKREG for bulk pricing, technical datasheets, and custom fastener solutions.